S-XPS 1645 AC Power Throttle Issue Investigation

I prefer to use Furmark and 8 threads of Prime95 Small FFTs. The Small FFTs test puts a consistent load on a CPU and doesn't fluctuate like LinX or IBT does.

The C0% in i7 Turbo is an indicator of how hard your CPU is working internally. During a stress test like this, each core should report 100.00%. If the C0% drops, that's a sign of clock modulation and the drop in the multiplier on each thread makes it easy to see a slow down.

 

Thanks for the reply bigcat!

i tried to do a test with furmark, and sure enough, on power (90w) the multiplier stayed at around 9-10.

On battery though the multiplier went up to 22! but my test score and framerate was lower. I guess that's because it's only stressing 1 or 2 cores?

With throttlestop activated (14x) i reached a score of 1326 on 130w power and the multiplier stayed around 14 for the whole test. My problem is that i do not know what a decent score for my system is.

I have a core i7 820qm, 4ghz ddr3ram 1333mhz and the ati hd 4670 card.

 

FYI...not sure if others have seen this, but someone posted youtube vids last month showing the gaming performanceo on the XPS 1645 using Crysis: Warhead and Call of Duty: Modern Warfare 2. Here are the specs:

Intel Core i7-820QM (1.73-3.06 GHz, 8 threads, 8 MB L3)
8 GB DDR3 RAM (1333 MHz)
Samsung PB22-JS23 (256 GB, SSD)
ATi Mobility Radeon HD 4670 (1-4 GB DDR3)
16" 1920x1080 RGBLED screen
DVD+/-RW

http://www.youtube.com/watch?v=V1BSSQaoyvA
http://www.youtube.com/watch?v=Sft1Zze1fhA

In the videos there is hardly any lag and if you read the comments, there is mention of this thread, but he didn't experience any of the problems that are being discussed here, nor was he using Throttlestop + 130W adapter.

Any ideas?

 

Got my new adapter now 150 w, did all the tests with throttlestop and my computer is no longer CRIPPLED WOHO

THX UNCLEWEBB U ROCK!

 

This may be a side note but I thought it pertinent to this discussion:

I was watching the last 44 minutes of The Hangover on blu-ray last night from a fresh boot with the 90W AC Adapter plugged in. At the start of the credits, I got the "For optimal performance, please plug in your AC Adapter." At this point I noticed that the blue ring on the adapter was off. I went to check the AC Adapter and it was super hot and smelled like burnt electronics. I decided to check the heat of the laptop and it wasn't hot, it actually wasn't even warm. I then unplugged the adapter, and then plugged it in this morning. The blue ring came on so I figure the adapter has some sort of heat protection mechanism built-in. I haven't plugged it into my laptop yet (fear of facial disfiguration) but I will later tonight.

Has anyone else had this sort of thing happen?

My fear is that I have a 3 1/2 year old and a 1 year old and with the AC Adapter sitting on the floor, with how hot it gets (would burn plastic if not skin) it could be quite dangerous. I tried to get a 130W but didn't have any luck in my past few attempts.

Pertinent specs: i7 720qm, RGBLED, 256GB SSD, 4GB RAM, ATI 4670 1GB, Blu-ray Writer (would've wrote "Burner" but I'm sure that would jinx me).

Thanks,

John

 

Can anyone explain to me why it is not throttled while on the battery? Is the battery able to produce more than 90watts?
I will receive my 1645 tomorrow (probably) and it comes with the 56W battery.. i don't see how it could run better on a 56W battery than on a 90W AC adapter?

 

You're confusing your units. The charger can supply 90 watts but the battery is 56Whr meaning it can supply 56 watts for one hour. It can supply more than 56 watts but obviously it would be for less time.

 

It never occured to me to check the wattage of the battery. This is a good point and worth investigating. Anyone have there system handy and can look at the battery label?

 

Ah, that makes sense ..never noticed it.
edit: So.. in theory this means that at max load (lets say 90-100 watts) my 56wh will last 35-40min?

ye would interesting to know.. but i dont think the W is mentioned on the battery? At least not on my vostro

 

I am facing a new issue with this laptop (RGBLED screen). Looks like linked to the power problem but nothing to do with the power adapter. This happened a couple of times so far.

Laptop was in low battery state (one was in sleep mode and other time it was shut down). I turned it on without having connecting the power adapter. System started as it would normally, but the screen was all in blue shade. No colors. The login screen (and everything) was in blue color shade and contrast/brightness was the lowest. When it turned on like this, I tried connecting it to the power but no change. I restarted it, still no change. Then I disconnected the power, shut it down, then connected the power back and started it - then the screen came back to normal.

Has anyone faced this issue?

When I called Dell Support, the guy told me this is because the battery was very low and screen does not have enough power - and this is alright. Well, I would say laptop should not start at all if the battery power is not enough to light the screen. Also the blue color should go away when connected to power, but it doesn't.

Please help me to figure if this is happening with only my machine.

 

You're most welcome. Glad I could help.

firuz19: No one here is claiming that the XPS 1645 is completely useless as delivered from Dell. It's not. Testing has clearly shown though that when gaming you will get significantly better performance if you invest in a 130 watt adapter and if you run ThrottleStop which allows the XPS 1645 to run at its full potential.

Without ThrottleStop, these computers will be limited by the bios to a maximum draw of 90 watts no matter what adapter you plug in. To achieve that limit, the CPU slows down externally which any software can monitor and it can also slow down internally by using an Intel feature called clock modulation. When these two throttling techniques are both active during a game, the performance can take a major hit. There's not much point in gaming at 25 fps when your computer is quite capable of 50 fps or more. Unplayable games will suddenly become very playable.

Also keep in mind how throttling works. The maximum limit is 90 watts but when it kicks in, it doesn't hold you at 90 watts. It drops you down to a miserable 65 watts and then slowly goes back up to 90 watts and goes through this cycle over and over again. There could be one section of a game where it looks good one day because you are getting close to 90 watts and all of a sudden the next day, it's chugging like crazy because the bios has decided to throttle your CPU so it is only consuming 65 watts. No one wants to do any serious gaming on a computer that is inconsistent like that.

You don't need a 130 watt adapter and ThrottleStop to use your laptop. I'm sure there are lots of games like Solitaire that will run fine with 90 watts. If you want your laptop to run at 100% of its full potential and you want that to happen 100% of the time then a 130 watt adapter combined with ThrottleStop is the one and only proven way to achieve maximum performance.

The only way to properly fix this throttling problem is to release a new bios and to recall all the 90 watt adapters and replace them with 130 watt adapters. I don't see that ever happening which is why users here are taking this matter into their own hands.

 

How low is "very low"? is it doing the emergency beep?
Why are you testing how low the battery can get and still boot up?
I am not going to try to boot on a empty battery just to see if my screen will die...its pretty clear that if you have the correct power to boot, it boots fine. if you boot on a empty battery its not going to perform correctly. With this said the tech is probably correct.
just my option not fact by no means.

 

I must also point out that Apple has none of these problems...

I own both, so I am not a fanboy or anything. Just saying, Apple has none of this nonsense going on.

 

Dude...one time I had a full battery and it was in the AC adapter, full brightness watching a movie. I unplugged the adapter and the screen just shut off. I had to go into sleep mode and out to get it functioning again.

I'd like to say all the small things I hate about this laptop are ultimately caused by the power issues, so yours, too.

Burner, hehe. I think the laptop is too protective, so burnt extremities should only come from the adapter and not the laptop.

Why am I so optimistic? WELL THE NEW LAPTOP CAME IN!! But, unfortunately *don't hate me!* I can't get to it until the 5th, where I will then send in this one.

~Ibrahim~

 

Not sure if this was already posted, but for anyone looking to purchase a 130 Watt adapter, here is a site that sells one...

http://search.store.yahoo.net/cgi-bin/nsearch?query=PA-4E&Go.x=9&Go.y=15&catalog=getpartsonline

 

Hi Unclewebb,
First off You are brilliant!!!,and why Dell doesn't hire you is beyond me. A quiet group here in Australia want to shake your hand. I have a question, since you were able to disarm the bios ludicrous power throttling policies, is it possible for you to edit a BIOS Update Package to change the parameters, and create an unofficial version of the bios to allow 130 W usage?

Just curious

Regards
Reece

 

Doesn't this mean that even using an 130 watt adapter is dangerous? I didn't catch where the 146 watt measurement was actually recorded, but from my understanding drawing more than 130 watts from an 130 watt adapter = scorched $2000 paperweight.

 

Thats actually brilliant if assessable. I know its not an easy thing to do and I wish unclewebb can do it. I know people from mydigitallife.com that re-did the BIOS package for dell adding SLIC2.1 to the bios tables. Im not sure if doing so means that its easy to edit the edit to remove dell 90W limitation, but its just a thought.

 

whut..37 dollars? that makes no sesne

 

Still unsure about my ThrottleStop settings. I have "Clock Modulation" checked and set at 100%. Do I need to check "Set Multiplier," and, if so, what multiplier should I use? Thanks.

 

looked here? http://forum.notebookreview.com/showthread.php?t=446193

 

Tenax: Thanks for the reply. The battery was not that low. It was not near the emergency mode, so no beeps or any message. My other laptop usually shows a msg to press F1 to continue if it is this low. I never got any of these msgs/beeps. The only way I could see it is running on low power was the power ring indicator was in amber color and blinking. It started like usual, and it started on lowest brightness/contrast and with a blue shade (no colors).

Any thoughts around this? Why this could be happening?

I did not do this intentionally; laptop happened to be on low battery and I had to take some directions so I never pluged in the power. It was on stand-by for some time. The other time it was actually shut-down and it booted up from start.

In one of the forums on Dell site (power adapter issue), someone posted about a green shade in some case (battery was not even low for him).

 

If you mean for him to make a custom BIOS lol, then that's a bit tedious. He would definately have to sell that [cuz of the amount of work he put in] AND that would DEFINATLEY void warranty AND any hiccups when flashing ur bios would brick your computer...and u can't send it back....

 

Yes, I did. Until recently it said you had not gotten around to posting recommended settings.

 

is it fixed now? i had it witten out below, but updated the image to reflect what it should be at to disable throttling. basically make it look like the picture

its important as i want it to be very clear, im going to get some clarification on some settings from uncleweb and add to it later.

 

Hi. A couple of interesting observations.

XBOX 360. No screen to power, no battery to charge. Brick? 175w.

PlayStation 3. No screen to power, no battery to charge. Power draw? 280w.

So, respectively, twice and three times what Dell apparently think is enough to run the 1645, with its screen and its battery.

Does not compute.

@UncleWebb: you wondered out loud if the throttling was to protect the battery rather than the CPU and GPU. But the laptop, on battery only, isn't throttled.

You also suggested that using the 90w adaptor with Throttlestop could be hazardous to the PC circuits. Though with the 130w adaptor, there is no such hazard (unless we buy Dell's FUD).

I've seen enough on here to realise that you know what you are talking about much better than I ever will; but these two points puzzle me. Can you please enlarge on these for me?

 

I would not call that FUD, at least not dishonest FUD.. they have just said the system was tested with 90W and not 130W. Any configuration that is not been tested has potential to damage the system, this does not mean it will, just that it is untested.

There could be an issue with the ability for it to supply more current than the 90W, which might be more than the XPS1645 could handle (at least over prolonged usage). I've tested with the 130W, the laptop does not get exceedingly hot, and it appears fine, just slightly warmer under load than the 90W allows. In my opinion, Dell just needs to validate this as ok, and get the supply out to their customers and a BIOS update.

You observations about the power bricks for the 360 and Playstation 3 are interesting points. The consoles are older tech's on a different silicon generation (higher power draw), slower clock (lower power draw), but net, should be similar power draw, not double a laptop. (hmm.. maybe the red ring of death could be fixed with a 90W supply... j/k)

 

No comparison man, they're not portable and have proprietary processors designed with little or no concern for power consumption. The Wii draws 18 watts, btw.

 

I had a green screen about a week ago. Did a reboot, walked away and when I came back, the screen was green. I shut down the laptop and restarted and was fine. I was running on AC the whole time. Not even gaming, just surfing the web.

 

Good questions Midnight_Voice.

Some users reported major problems when running Furmark + Prime95 which draws well over 90 watts and then immediately switching from their 130 watt adapter to battery power. This was enough to kill the battery and for the computer to shut down within about 10 seconds. More than 1 user reported the same thing.

If you can't switch smoothly from using more than 90 watts directly to battery power then maybe that was Dell's motivation to limit these to 90 watts when plugged in. If that was there motivation then I can guarantee you that there will never be a bios fix to fully support a 130 watt adapter.

It has been proven that these laptops throttle less on battery power which means they are quite capable of drawing more than 90 watts from the battery without damaging the motherboard. That tends to poke a hole in Dell's FUD theory that 130 watts is dangerous to the motherboard.

Just to clarify. Using ThrottleStop with a 90 watt adapter could result in your computer trying to draw more than the power supply can deliver. That could easily damage your power supply. If that did happen, it's anyone's guess how much voltage your motherboard or CPU could end up getting when your 90 watt adapter has flames shooting out the sides of it.

From all reports so far, using ThrottleStop with a 130 watt adapter seems perfectly safe as long as you don't fully load your computer and immediately switch to battery power. I'm not sure what the results would be when playing a normal game and switching to battery power. Furmark + Prime95 is overkill compared to most normal work loads.

Edit: These pictures should explain Dell's decision to be conservative with the power draw of these laptops.

http://www.theinquirer.net/inquirer/news/1042700/dell-laptop-explodes-japanese-conference

 

@myabhi

I just experienced the same problem with my RGBLED 1645. Except my machine is constantly plugged in with 130w adapter, and the battery was full! I got my machine the day before yesterday, and this was the first time i've experienced it. I was watching a flash video clip, and everything suddenly turned blue.

@unclewebb

Thanks for the tip! I've obviously not stressed my system enough with the earlier tests i did, but the furmark + prime95 combo did the job! Sure enough, the multipliers went down to around 9x when i stressed both the CPU and graphics card at the same time. The C0 on all 4 cores also delivered well below 100%. When i used throttlestop with the 130w adapter, the multiplier stayed at a constant 14x the whole test. Thanks alot!

 

As a work around would setting the max unparked core to say 50% allow the turbo mode to kick in during gaming to increase fps on single threaded games?
See this thread for registry settings

 

Hi all and thanks for the help and support with this issue. I'm not a computer expert but I still have a question for you.

I have a wled sxps1645 with standard PA-3E 90 watt AC adapter. I tried running an old game (battlefield 2142) that even my 2 years old 400$ dell inspiron 1501 could run well. Everything is fine during the first 30 minutes of play. I have great fps and the game runs smoothly. But after that the game starts to slow down and it is unplayable. I also notice that the back of my laptop is really hot and that the AC adapter is fairly warm. If I follow your explanation regarding power consumption (and I must be wrong) but would not I get bad frame rates when I start the game or after a few minutes I'm in the game? Do the fact that the slowdown appears only after 30-45 minutes when precisely the laptop get really hot on the back and also quite hot on the trackpad means that it could be temperature related?

Thanks for your help

 

It's not temperature related (unless you're hitting temps around 100C), as the laptops power consumption approaches 90W the bios throttles it back down to around 65W if I'm not mistaken and from there the cycle continues, which might be why you don't see the issue right away.

 

Im not sure if i have done the test like i should, but plz have alook at my pic and say if this show throttling problem.
http://www.ladda-upp.com/bilder-a/test09-222.png

 

That takes me to some uploader site, no picture.

 

http://img27.imageshack.us/img27/3954/namnlstest.png

maybe this will work

 

If I'm not mistaken your multiplier is lower than it should be which is indicative of throttling, so yeah you're affected; welcome to the club.

Edit: I might be reading it wrong though, an easier way to check for throttling is to run the newest version of realtemp and then stress the system (GPU & CPU) it will appear above the thermal status, when throttling occurs it says: Clock Modulation.

 

OK tnx... another one... everytime when i want to stream a movie , like on youtube , internet exp get stucked. why does it that ? , something i need to install or is this related to throttling ?

 

I don't think that's related and that could be any number of things, try another browser maybe? I personally prefer google chrome, it's far faster.

 

How come u get 1700+ k score at fumark?
I only get like 1200-1400:/

 

So what's all this talk about the 1645 being discontinued with the i7? I can still select it but some can't

 

I don't think that the i7 SXPS are actually being discontinued. I have now chatted with Dell Sales and called Dell and both agents have told me the same thing, that you can still order both the i7 720 and the i7 820... You can still order them through US Dell.com and Canada Dell.ca. I'm not sure why people are getting different results, but it appears that Dell is not discontinuing these machines.

 

After some testing, I noticed that once the consumption has exceeded the 110w and I press a key on the keyboard or when I move the mouse, consumption goes down to 65W and suddenly the pc freeze. Whether in play or bench (fumark + Prime95), when I move the mouse or I press a key on the keyboard, I have very low fps, the mouse cursor to freeze etc ...

When I release the key or that I stop moving the cursor, the consumption backs over 110w and I have no freeze

I think there's another problem at this level in addition to the power issue

EDIT: With external mouse or keyboard, I haven't this issue.

 

duno ... this was with the adapter... have not test it with just battery

 

I've had all sorts of issue myself with USB devices. With the Logitech G5 Laser mouse, it spontaneously would reset itself and I'd lose my custom resolutions (it has buttons for on-the-fly mouse speed adjustments). My external 2.5" enslosure with a Seagate 500G 7200 400mAh power need, whether connected to USB or eSATA, and regardless if I used external power with it, will disconnect itself or malfunction during large file transfers (ie 100GB+) if I continued to use the computer during the copy process. I think the problem is related to using the keyboard and changes in CPU usage while it's going. Also, I noticed audio problems and weird glitches are frequent, like with a batch transcode of 2000 WMA Lossless files to WMA lossy files, 150 files turned out corrupt or some type of error occurs. With the 90-watt adapter I have noticed the Bluetooth light turns off during use, but doesn't when on 130-watt.

Simply put, 1645 has some serious problems outside of throttling. I am getting throttling now even with a 130-watt and High performance power setting on Windows 7 with a single WMA encode, I'm running a batch encode of WMA files and the CPU just sits at 933MHz and only one core spikes to 1500MHz occassionally, whether I run one instance or 8 the CPU never ramps up. CPU usage never ramps up either and it just seems to go slowly.

I've had the 1640 and two 1645's to test this on, it only happens on the 1645.

 

fr0x: There is definitely another issue going on. It might be a keyboard / mouse driver issue. Most users report that this issue goes away after you enter and exit standby mode or if you use an external mouse and keyboard so you are then using a different driver.

reecepeart: I think we need to give tinkerdude most of the credit here. He is the one that took the time to write a 59 page pdf that clearly showed what the Dell bios does to throttle a CPU. Now that he's been muzzled by Dell, we can't hear from him anymore.

Tinkerdude was using his Latitude E6500 but when I found this site and asked users to do some testing, I found that the XPS 1645 with a Core i7 mobile CPU uses the exact same method to throttle and slow down your computer. This is obviously no coincidence.

Within a few hours after reading the tinkerdude throttling bible, I had some code up and running to monitor for throttling and to reverse it as soon as it is detected. He showed me the exact MSR values that were being changed.

I'm not that smart and have no idea how to hack and rewrite a bios. All a modified bios would do is risk bricking your laptop and/or voiding your warranty.

I'm not sure if anyone knows this yet but the beauty of ThrottleStop is you can rename it to whatever you like so it will be a lot more difficult for anyone to find it on your hard drive. If you called it PacMan then it would create a new file called PacMan.ini and would save your settings in there. No one would expect that PacMan.exe is some sort of dangerous throttle blocking program.

In comparison, a modded bios would be a big red flag.

gaah: Are you using ThrottleStop? Can you post a screen shot of that and i7 Turbo while you are encoding so I can have a look?

 

I don't have ThrottleStop - can you email me the latest version? [email protected] - I can also mirror it on strags.com for everyone. Please send the latest i7 Turbo test program, too.

 

http://forum.notebookreview.com/showthread.php?t=446193

it should be all on here.

 

Are you sure you used the same resolution?
I got a 2230 furmark score at 1024 x 768 resolution.