S-XPS 1645 AC Power Throttle Issue Investigation

okay, ill have to do that ina few hours, seems i have to go and fix something. lol

i was satisfied after my gaimng problems went away, but ive never really checked to see if that fixed my throttling....if not, i shouldve just bought the 720qm.

 

I've been reading (most of) this thread with quite some interest as I'm about to order a 1645 with 720/256SSD/RGBLED/4G, and therefore will probably run into this problem while gaming.

What I'm wondering is this, and please excuse me if this has been discussed before, I haven't found it.

1. Had anyone tried the test without a battery installed? Could the charging of the battery cause a problem?

2. If I understand correctly, the i7's determine their max overclock partially based on temperature. Could the reverse also happen and therefore downclock the i7? Maybe the cooling system is part of the problem? I wouldn't know why using a 130W brick would help in this case, but then again I'm no expert in this field

3. Has anyone noticed the throttling during 'regular' work? I'm buying the machine to do development work on, and plan to run a VM next to Visual Studio and SQL server. MY guess is that it will do just fine, and I will just have some trouble while gaming.

 

Just Google JU012 adapter and you will get many places to buy from. You should try to have Dell ship one to you for free.

Note: Make sure that it is the New Slim Model

 

Yes, this doesn't change the behavior.

Turbo boost lets it "overclock" one or more cores when there is enough temperture headroom and there's the right workload. But the CPU should atleast be able to hit the 12x multiplier (on the 720) even without turbo boost. Also the tempertures don't seem to be an issue on this machine.

It's really hard to measure because under normal workloads most of the CPU cores enter idle states and it throttles constantly under normal operation. So unless you deliberately load the CPU with some benchmark/game/test its not possible to determine if its underperforming or not.

 

The new BIOS update A03 is out. Has anyone tried it out yet? Does it solve the problem? is it any better?

 

So much for my contribution

I have an i7 860 in my desktop (which is why I now also want an i7 in my laptop ), so I did some reading into the i7. What you say makes sense, and if there is no temperature issue, there goes my theory.

I'm using this sidebar gadget to monitor the cores (can't remember its name) on my desktop, and during regular work a few cores sometimes peak out, but hardly ever all four (or eight threads). So I assumed for work I'd be fine with the 1645.

Thanks for the info.

Mine is scheduled for january 25th, so maybe they are working on something and delaying deliveries for a while... Once it gets here I will let you all know what's up (BIOS, powerbrick, etc). And I will keep my eye on this thread...

Can anyone compare an 720QM to an 860 from experience? I know my current laptop (P8700 @2.53Ghz) is terribly slow compared to the 860, and the 720 won't work wonders, but I'm hoping the extra threads wil help a bit, and hopefully the SSD will do some good as well.

 

look forward to your results.

looks like dell really does want to get my laptop, which i reluctantly agreed too as long as theres no interruption etc. I was thinking this is probably a good opportunity to put all our testing results / utilities etc, on the desktop so that they have the info right in front of them. Hate to do the work for them, but we also want this problem fixed.

anyone with results and specs ill put in a document for the "engineers" to see hopefully.

 

So I'm trying out a few things while bored at work today with the brightness part of the problem. You guys all like Prime95 and Intel Burn Test, but I'm more partial to Cinebench 10 64-bit mulitcore test for pure CPU pushing.

Cinebench10 64 makes all C0 states stay at 100 for the test duration, so I decided to try it in conjunction with Furmark for some AC tests.

Setup: 720qm, WLED, 90w IN, restart after every test, battery NOT fully charged.

The 1645 has 15 levels of brightness, which work out to about 7% per, give or take.

Test 1: CB10 alone
All brightness levels have no effect, multiplier runs solid ~12.1x for entire test, with all C0 levels at 99.9-100.

Test 2: CB10 w/ Furmark @ 800x600 (window)
I start Furmark with the render toggled 'off' (spacebar) which means the GPU is doing no work. ~12.1x multi and ~100 C0. When Furmark is toggled 'on', the multiplier immediately drops to 7.0, and the C0 level is halved. This is at '0%' brightness.

Test 3: Furmark alone, 800x600 window, incrementally increasing brightness every 20 seconds
Every time there is a brightness increase, the multiplier dips to 8.0-10.0x, but soon rises back to 9.5-12x about 1-2 seconds later. Once you pass brightness level 12, it begins to dip to 7.0x before rising back up, but starts to fluctuate between 7.0-9.0x. At level 14 (1 below max), it locks down to 7.0x, never to rise again. C0 levels averaged ~14-15% the entire test.

Test 4: Furmark alone, 1024x768 window, incremental brightness increase again
More or less the same deal as above, except this time it bombed down to the 7.0-9.0x multiplier at level 9, and settled on level 13 at 7.0x. Interestingly, at levels 11/12, it would drop to 7.0x and hang, but rise to 8.0x at times. The C0 level was anywhere from 11-20%.

Test 5: Furmark alone, fullscreen 1600x900, incremental
Level 0 runs at 10-11x (no higher). Level 4 shows 8-11x. Hits 7.0-9.0x at level 7. Basements (hits 7.0x permenantly) at level 12.

In summation (TLDR): The less intensive the GPU use, the higher the brightness can be before the CPU basements. Fullscreen gaming is best done at levels 0 through 3, but doesn't stutter and drag-lag till ~12. I assume the numbers are probably even lower in more intensive games.

 

What version of the BIOS do you have?

 

post your full specs if ya could. thats cool your cpu doesnt throttle under the intel test, is that after the fans etc start going? i have the 1080p screen maybe that takes more power? as the intel test seems to put it right on the very edge of throttling for me anyway. ill start saving these.

it does seem to be a balance between gpu load and cpu load. furmark loads the gpu 100%. I would assume that if you just load 1 core with prime95 or whatever, and start furmark you would get the same throttling. Much like i see on my own machine.

 

Just finished some Wattage testing, found out how much each part is consuming and how much Wattage this system needs on full load...

Battery fully charged consumes 9W
Idle System/LCD off/No battery/Wifi On = ~27W
RGBLED 16W max brightness 7W min brightness
Wifi Chip connected to N network 2W
Speakers 7W
Video Card Maxed 27W + Idle System Wattage
Processor Maxed 37W + Idle System Wattage

Total comes out to around 114Wats without the battery plugged into the laptop

With battery plugged into the laptop 123W.

This is the total system wattage to be expected with everything running and turned on with the system on MAX.

 

What sort of temperatures are people seeing with the 90W and again with the 130W? I have an IR thermometer and see about 169F (76 C) on my 90W. So hot that it left a mark on my desk. I stopped letting it charge at night. Too worried about a fire. I've got to talk with Dell about replacing it. Just wondering if it really runs cooler.

 

the 130w runs a lot cooler.

good stuff siphen, can ya comment any on the wattage limiting itself? i find that its very well capped at 90w, and as it approaches 90w it starts throttling. Ive seen it spike up to 120-130watts on the meter before immediatly throttling down. did you use the intel burn test or prime 95 to max the cpu? curious because i think the intel burn test is a lot more demanding.

ill try to do your tests, if you mention the programs you used for comparison.

 

Alright so that means the 130W should come standard with these machines

 

Yeah its certainly starting to appear that way but at the same time, that isn't really a fix, seeing as you'd need to adjust hardware components to make use of the 130w adapter. So probably new Mobos?

 

This is what the A/C adapter consumes, not the actual laptop part? I'd assume the A/C adapter consumes far more power than what it outputs to the laptop especially since it's also a space heater.

 

I got some very different results. heres mine so far, im not sure a good way to test the gpu itself as the cpu comes up with it and starts throttling half way..

base sys, no wifi, dim bright = 31-32 watts
prime 95 = 81 watts difference 49 watts
intel burn = 90 watts difference 58 watts

base sys no wifi max bright = 36watts

Whats interesting is the only4-5 watt difference on the wled screen between max and min brightness. prime 95 seems to pull 9 watts less then intel burn test, confirming my theory the intel burn test does stress more as they say.

but the processor wattage is extreme, 58watts under max conditions. I assume this includes possibly other power usage from memory or something? but i ran it again to make sure the gpu had zero load, and it had nothing.

I used the 130w for these tests, since i believe its more efficient at these power levels then the 90w, giving more accurate readings.

 

This was tested on the A02. Tomorrow I'm doing the A03 for comparison.

Also, my specs are now posted below.

 

if that was the case, why would the 130W solve my gaming issue?

 

good question...

Now another Question Max420

What kind of games are you playing? anything non intensive as to not cause throttling? OR are u playing CPU and GPU intensive games like Crysis , Dragon Age, GTA 4 etc etc

 

i just bought my laptop about a week ago and it is already on its way, should be here early next week. i got the i7 720, rgbled, and the rest is standard. would the 130w adapter help me run my games on the highest setting with the brightest settings without "throttleing down"

 

I’m running Intel Burn Test V2 and i7Turbo to verify as well as FurMark.

My idle with my RGBLED range from 24-29 LCD off to 40-45 LDC on max bright. I turned my monitor off by setting it to turn off after 1 min in power management. Same thing done when running the burn tests, I did them all with the monitor off to verify I wasn’t hitting the 90W cap while doing the tests. You need to make sure you minus the wattage you’re pulling from you idle wattage to get accurate CPU and video wattage results, when I wasn’t doing it right my wattage numbers where over 150w

I don’t know the efficiency ratings on the 130W slim adaptor which is what I’m running on now, regardless the system caps the intake into the system at 90, I’ve seen it jump up to 108 some times. I need to see if I can get my system to max out both the video and graphics while the monitor is off without hitting 90W

You have to also keep in mind that as the system heats up the fan spins faster and starts consuming more watts as well.

From the looks of it, dell will have to release a 1646 XPS16 to correct this issue.

Anyone that got the 820M i7 just wasted their money on that upgrade until this is fixed. If at all.

It’s like driving in a car designed to do 200 but with a governor only allowing it to hit 150

Don’t get me wrong, I love the laptop, it had everything I wanted in it. But I’m not going to allow a $350 processor upgrade be wasted because dell was too short sighted not to see this.

I was shocked to see the battery consumes 9W when its fully charged.

 

No , I don't think so, I think we should wait for a fix from dell which may never come. Earlier posts suggest that using the 130W adapter for too long might damage your motherboard [@ least the connection to the AC power]. Though some ppl disagree I really dont know what to believe at this point. I mean the latitudes from last year we're having a throttling/overheat issue and there's still NO fix. So I hope we're not fooling ourselves and thinking that dell is actively trying to help us.

 

At idle and dim brightness with wifi off it was 32 watts very very steady. at max cpu load with intel burn test it took the full 90w out of the wall, thats with no gpu whats so ever. thats how i got those differences for cpu only wattages. is that not how you did it?

Thats the way you mention right? ive seen spikes 130w+ when loading the cpu then hitting the furmark.

using intel burn test, with the same 32watt idle and then loaded to 100% load
7x mult = 61w from wall
12x mult = 90w from wall

it would seem the problem being the cpu sips power when not used,

 

I did my math wrong, let me correct myself...

Battery out of the computer, no wifi, LCD off Intel burn test set to max and 8 threads.

Pulling 85W
Idle without running Intel burn is 25W

That means when maxed out the i7 is pulling around 60W

Furmark pulls 72W - 25W means ~47W

that means this laptop can pull a full system load of 155W at max without battery, 164w with battery, not including the watts needed to charge it if its drained.

id recommend the 210W adaptor for home use if you going to game on it like crazy, unless dell has something between 150w and 210w

 

You're assuming the amount of power the a/c adapter pulls from the wall increases at the same rate the laptop component power consumption increases, I doubt they're that proportional. Also the amount of power the a/c adapter draws likely increases as its temperature increases and efficiency goes down.

 

I’m adding the numbers up biased on the tests ran, no matter what size adaptor you plug into this laptop it will only pull a constant 90W no adaptor will change that, it’s either encoded into the BIOS or it’s a system board limitation. This has already been proven; even the back of the laptop says 19.5v/4.62A (90W)

Granted the total will not be 100% accurate, that does not change the fact that if you're running at max this is going to be around the amount of wattage the system will pull during stressfull use

 

okay then our test seem to agree with mine then siphen yes? i was just tryin to figure it out, as there seemed a discrepancy.

This laptop deff has performance being unused especially for gaming. Inspired I pulled the battery, went to external monitor, turned off wifi did everything i can to lower the power consumption. In TF2 where i usually get 40-45fps looking in the same direction i got 60-70fps and no matter where i looked i couldnt get it to drop lower then that. It played amazingly smooth for me just moving around. I noticed the cpu mult was a lot higher, and the gpu load was 20-30% higher.

 

Siphon..
A couple more questions..
Does Furmack not use the CPU at all? You are assuming idle, but it should to be using more than idle.

other than that.. good data, I just don't agree with the overall sum, but I do think it's more than the 90W can supply, even considering it's lost efficiency.

 

When furmark is running the processor is showing 2-3% utilization on all 8 threads.

 

That max is biased off the extreme, playing music on max volume with laptop speakers, 100% cpu, 100% video, etc, etc. you will almost never reach that amount of wattage used. Dell made the mistake thinking we would never use more than 90W on this laptop.

Considering the fact that the Kill-A-Watt shows an output of exactly 89-90W nonstop and nothing more, shows that there is very little loss, if any. If there was loss using these AC adaptors then we would see it pulling around 100-120W but it’s not. We shouldn’t be comparing this to a desktop PSU; this device is showing the exact pull the laptop is draining from the wall.

 

from my observations i would agree, what its pulling with the 130w is what its pulling from the computer. with a 90w its like 2-3w more but its at the limit where the efficiency would be less.

There are power supplys on desktops that reach over 90% efficient, it would make sense for a power adapter for laptops to be super efficient to avoid getting to warm. price of the adapter etc points to the same conclusion perhaps.. all signs point to the adapter being effecient, it may be a watt or two off but i would think its pretty good reading.

edit: IV symbol printed on the back of the supply is for high efficiency. to get that reading the average efficiency of the adapter has to be at least = or greater then 85%., given were operating in the max efficiency zone on the 130w it should be pretty accurate.

 

This is disappointing...probably means I'll want two different power bricks. Something around 150 for powering the laptop at my desk, and the 90 or the 130 for when I'm out and about.

 

OK, as you all ready know I use the 1645 under normal computing use. Dell has sent me the 130W adapter the other day and since the A03 Bios update my 130W and 90W brick is basically the same temperature. They were both mildly warm to warm under the conditions I use my computer so I now sent back the 130W adapter as I do not need it. I guess that if you are going to be stressing the 1645 you will need the 130W adapter but I can definitely say that under normal conditions the 90W adapter is not hot at all for me and do not need the 130W adapter. Yesterday I ran the 90W adapter for 12 Hours straight and it did not at all get hot.

 

Discharge your battery and then try that agian.

 

Running Furmark on my machine in xtreme burning mode (needed to properly max the graphics out) one of the processors runs flat out and the others all have a little activity, presumably background processes.

I agree that the machine is pulling more than 90w but I think calls saying it needs a 210w adapter are way far of the mark.

 

Didn't know crysis was cpu intensive

 

Can someone try Star Wars: TFU? or Red Faction Guerrilla? Both are supposed to have somewhat heavy physics mechanics and they both have decent graphics.

 

Well that works better for some and not so well for others, from your sig I see you have the WLED, the issue is worse for those with the RGB display

 

Hi guys,
I been following this post for a month now. I have seen mixed reactions for this laptop. What do you guys think? is it worth the money?? What is the final verdict for AC power throttling?

Regards

 

if you do not upgrade any parts on this system, and get the complete base model, its worth it if you get it on sale (a good sale), if your looking for a laptop to play games on, look elseware for now, until dell fixes this issue.

 

I have discharged the battery and used my laptop as I usually do and it did get hot which is quite common if you are charging and using the laptop at the same time, but I was able to hold it in my hand which would make it mildly hot which is acceptable and should happen when doing both at the same time.

Thanks for the tip.

 

I wouldn't classify the problem as significant enough for return or to shop elsewhere. Performance is still high-end and games are playable. Some guys around here are acting like the thing doesn't work at all, but it runs quite well -- and in the future you can expect it to run even better, once the i7 kinks are fixed.

 

So let me make sure I understand this... You're simply running various tests and measuring the difference in power draw?

Too much room for misleading measurements. I just about completly disagree that this machine is pulling up to 164watts. Even Dell wouldn't screw it up that bad.

 

I happen to like it a lot and think it is great but everybody has different needs. Like I have stated before I have not had any issues with the 1645 at all, but I also am not a gamer and even then I have heard that it is only certain games.

 

everything but the gpu seems pretty spot on, as i havnt tried to measure the gpu.

I would have siphen check the load under the furmark test to make sure its not using the cpu, as it does load at least one core for me.

From my own measurements it would be pretty safe to assume the laptop i have could probably easly put even the 130w to its limits if it were to have everything normally hooked up and stressed. Ive seen spikes of 130w+ before it has a chance to throttle.

Dells already majorily screwed up. The i7 is a beast that can cause the system to throttle without any help of the gpu. Siphen does have a very valid point, people are probably wasting a lot of money on the 820qm etc. Given the problems and time table the latitudes have its hard to be optimistic but shal try.

 

Does playing a blu-ray w/the volume cranked up and the screen brightness on high cause a problem? I would think this would cause a major power draw.

 

1. Is it normal that after 30 days of usage my 90W power supply got bubbles under the black sticker ?
It also smells like an iron ...

2. How many complains you need to make to get a new replacement ?
3. Is there a rule that after 3 complains they should offer new laptop ?

So far had:
- noises on the mainboard,
- dust under the screen
- performance problems
- extra hot power supply

and today I've runned my laptop on battery for 1h and I've noticed strange sound comming from battery - something like moskito or water leaking ... bizzare.

I still want to keep the laptop cos I like the design, screen and external build quality....

 

As i stated before, this machine is wonderful but for gaming.
This notebook will be very good for almost every task, even when throttling only demanding games or 3d application will suffer.
The reason for not buying or returning the notebook is the lack of trust in DELL fixing the problem as it took them so long to try to fix the Latitude series. In addition Would you be interested to pay premium and tolerating not getting the maximum out of what you paid, you better off with cheaper notebooks that will guarantee the maximum performance, here is a list of other with a comparison
DV6t ( a lot cheaper, No HD 1080)
DV7t ( a lot cheaper, 17" vs 16")
DV8t ( a lot cheaper, 18")
Envy 15 (much more powerful, more expensive)
even for the studio 15, Asus,.....
After reviewing my options, I decided i can live with the 720P dv6t, and was able to score one off ebay brand new @ 850 including blueray, bluetooth, and fingeprint reader after 20% BCB. You can get it regularly around $950 from HP. Not the perfect laptop but for the price it is a steal.
At the current performance of the XPS 16, the DV6t will arguably perform a little less or at bar.

 

4:09:37 PM System Connected with BE_HY_Khaja
4:09:37 PM BE_HY_Khaja Hi
4:09:47 PM BE_HY_Khaja Welcome to Dell's Sales Chat! I hope you are doing well and thank you for waiting. My name is Saman.I will be your personal sales chat advisor today. I can be reached at Email [email protected]ow may I help you?

4:09:55 PM ######### hello
4:10:12 PM ######### I have a pretty technical question regarding my recent purchase
4:10:25 PM ######### it has not shipped yet so this is just a general inquiry

4:10:39 PM BE_HY_Khaja okay

4:11:01 PM ######### The Studio XPS 16 with i7 820XM and RGB LED screen has had a throttling issue apparently are you aware of this issue?

4:11:43 PM BE_HY_Khaja To be honest i am not but if you can explain me that probably i can answer it

4:11:56 PM ######### ok
4:12:07 PM ######### here is a thread regarding the issue; http://forum.notebookreview.com/showthread.php?t=437800
4:12:51 PM ######### The issue is that the laptop throttles when being loaded. I just bought this laptop yesterday and it is being confgured. My question is two fold
4:13:20 PM ######### 1. Is this laptop going to be shipped with a 130w power brick and 2. Has the issue been resolved via a motherboard update.

4:14:03 PM BE_HY_Khaja The issue has been resolved as we donot have any reports as per this issue from the customers

4:14:20 PM ######### one moment
4:14:55 PM ######### http://en.community.dell.com/forums/p/19306277/19596373.aspx#19596373
4:15:04 PM ######### The most recent post was 2 days ago

4:16:34 PM BE_HY_Khaja that might be a refurbished system

4:17:17 PM ######### Ok is there anyway you can tell me if the system will definately be shipped with the 130w power brick or the 90w power brick. The invoice did not mention this.
4:17:41 PM ######### Dell Purchase ID: 9######6144
Customer Number: ########646

4:18:14 PM BE_HY_Khaja let me check

4:18:20 PM ######### thank you kindly
4:19:03 PM ######### also if the issue has been resolved is there an official statement from Dell that the issue has been resolved?

4:19:38 PM BE_HY_Khaja okay
4:21:20 PM BE_HY_Khaja I am not able to get that information
4:21:45 PM BE_HY_Khaja but you donot need to worry as if incase you get any problem DELL would take care of it

4:22:46 PM ######### You could not find out the info on the power brick or an official statement from Dell regard the throttling of the Studio XPS 16?
4:22:56 PM ######### regarding*

4:22:56 PM BE_HY_Khaja yes

4:23:21 PM ######### so you do not know on either one of those issues?

4:24:21 PM BE_HY_Khaja there we few issues reported but it has been taken care,earlier it was in XPS 13.You donot need to worry about it

4:25:57 PM ######### The XPS 13 does not have either the RGBLED or the i7's. Who would know about these issues regarding the Studio XPS 16? Is there a number of someone who would know? I understand you might not know about this issue but surely there is someone who would.
4:27:25 PM ######### I'm not trying to be too forward but it is a very technical issue and I am paying 2000 dollars for a product that might be broken.

4:29:53 PM BE_HY_Khaja it wont #########
4:29:58 PM BE_HY_Khaja It a very rare issue
4:30:58 PM BE_HY_Khaja Its not important that if one thing happens to a product,it will happen to all the laptops

4:33:38 PM ######### While I realize not all problems happens to the same products we are talking about a throttling issue with a very specific model. It has been documented in a 100+ page forum post by every single member who has the product in hand. Thank you for your time but I'm afraid I will have to cancel my order if you can not provide an answer to either question. You have been very helpful.

4:35:14 PM BE_HY_Khaja As i said earlier the issue is rare and mostly its a refurbished system

4:36:37 PM ######### Thank you for your time, all members who had issues bought thier models brand new from Dell so unless Dell is in the habit of selling Refurbished systems as New you are mistaken.

Thank you again for your time.