E1505 RAM Question

I just recently purchased a new E1505 with the following specs:

Intel® Core™ Duo processor T2500 (2MB Cache/2GHz/667MHz FSB)
Genuine Windows® XP Media Center Edition 2005
15.4 inch UltraSharp™ Wide Screen SXGA+ Display with TrueLife™
1GB Shared Dual Channel DDR2 SDRAM at 533MHz, 2 Dimm
256MB ATI MOBILITY™ RADEON® X1400 HyperMemory™
60GB 7200rpm SATA Hard Drive
Integrated 10/100 Network Card and Modem
CD/DVD Burner (DVD+/-RW) with double-layer DVD+R write capability
Intel PRO/Wireless 3945 802.11a/g Mini Card (54Mbps)
85 WHr 9-cell Lithium Ion Primary Battery
2Yr Ltd Warranty, 2Yr At-Home Service, and 2Yr HW
Carbon Fiber QuickSnap™ Cover

$1,647.00 after -$750 + -$35 + Free Shipping

My question is, the first thing I am going to do is upgrade the RAM from 1GB DDR2-533 to 2GB DDR2-667. While browsing through Newegg, I came across this:

http://www.newegg.com/Product/Product.asp?Item=N82E16820231066

Should this run in a E1505? I know PC5300 is compatible, but I have no idea about PC5400 (I had no idea they even made PC5400 notebook memory). Just the fact that it is CAS 4 seems reason enough to give it a shot.

Thanks.

 

It might work, but I know people had problems running PC4300 in PC4200 slots. Also the 667Mhz does offer that much advantage to speed over 533Mhz.

 

Oh I know, I just opted for the 667 since the price difference was insignificant.

I went ahead and ordered the G.Skill PC5400 (appartently the last batch Newegg had), hopefully all goes well. I have used nothing but Corsair and Crucial over the years, hopefully going to an 'off-the-beaten-path' brand won't prove to be a mistake.

 

Well I have never used GSkill, but I have used Transcend and they are good. Like I said, I don't know if the 5400 will work in the 5300, but I guess you will be the guinea pig.

 

I have a stick of 512MB ddr4200 g.skill running in my e1505 as I type this, no problems to speak of as of yet.

 

Hey: DSMav8r - please do report on how it performs.
According to the single review on NewEgg: "No crashes yet or misbehaving in my E1705 / 9400 from Dell."

 

How much for these sticks? I paid an extra $180 for the extra gig in my ordered 1505, just to make it easy on myself.

 

My salesman told me that I had to have the same size ram dimms in each slot with the e1505, is this true? I hope not, i'd like to buy a 1gb to stick in the one free slot I have. (512mb currently) ((well, not currently, en route).

(btw: been lurking around this forum for a few days, I think I've read every thread regarding the e1505 and the 6400, thanks for all the great info, you'll be hearing more from me that's for sure)

 

Well, I am happy to report that the G.Skill PC5400 RAM works perfectly...No issues whatsoever.

I will run some benchmarks later and see if there is really any difference between these and PC5300 sticks.

 

As with all newer computers, you should match memory modules. If you have a stick of 512MB brand a, you should add another stick of 512MB brand a memory. I have no experience with the Duo Core yet (e1705 on the way), but if it's anything like Intel's HT processors, you must have identical sticks of memory, otherwise the HT abilities will not work. My wife's older Inspiron 1100 notebook requires identical sticks, so your salesperson may be correct.

My advice: buy two sticks of 1GB and replace your 512MB stick.

 

Hello, i just bought the e1505 and am wondering if you have performed the benchmarks for the new ram? vs old (slower) ram. I dont know which ram i should get yet. and how much did you pay for the 1 gig pc 5400 ram?
Thanks in advance!

 

this is inaccurate. you don't need to match sticks. in fact, the newests MBs are even dual channel capable without matching sticks. as long as you have the correct specs; i.e., the ram fits in your computer, you are good to go.

 

Fine print on the e1505:

http://www1.us.dell.com/content/pro...05?c=us&cs=19&l=en&s=dhs&~tab=specstab#tabtop

2 Dual-channel memory requires 2 each of the same capacity memory DIMMs.

Personally, I'd get two memory modules of the same brand, size and speed for best stability/compatability with Dual Channel operation...even if the motherboard was capable of mismatched Dual DDR operation.

 

dual channel operation REQUIRES same capacity chip in each slot. it does not require that the chips are of the same brand/manufacturer or even timings.

You do not need to have the same size memory in each slot on the Dell systems with Duo Core, but it won't run in dual channel mode. It is probably best to maximize memory within budget (at least up to 1GB), then worry about dual channel or not. Meaning, you're probably better off with 1 stick of 1GB (or even 768 = 256+512) than 512MB dual channel (256MBx2). After that, only the most demanding users are going to notice the difference between >1GB (asymmetric) and 2Gb dual channel. (assuming 1GB dual channel is sufficient for average users).

also, as absurd said, buying a kit (2 matched sticks) is your best bet; second is two sticks same model/brand; third, same size any brand, .....

 

dual channel does NOT need the same capacity sticks to run. only on the early gen MBs is this true.

there are screen shots on this forum with people runnin 1 + 256 in dual channel

 

I don't think it is possible, should be able to in single channel

http://en.wikipedia.org/wiki/Dual-channel_architecture

 

Dual channel just means both channels are populated, not that access is symmetric. Capacity has to be the same for accesses to occur on both channels simultaneously (virtually).

The following is from Intel specs on the chipset in E1505/E1705 family, wrt memory controller.

Intel 945GM/PM chip set supports dual channel DDR2 in three modes

Single-channel (single SODIMM per channel)
Dual Channel Symmetric
Dual Channel Asymmetric


Dual-channel Symmetric Mode

This mode provides maximum performance on real applications. Addressess are ping-ponged between the channels, and the switch happens after each cache line (64-byte boundary)..... [edited] . The drawback of Symmetric mode is that the system designer must populate both channels of memory so that they have equal capacity, but the technology and device width may vary from one channel to the other.

Asymmetric Mode

Trades performance for design flexibility. Unlike the previous mode, addresses start in Channel A and stay there until the end of the highest rank in channel A, then address continue from the bottom of channel B to the top. [edited].... The system designer is free to populate or not populate any rank on either channel, including either degenerate single-channel case.

 

ok...so now..I am confused..

In order to run dual channel, do I have to have two sticks ? or I can use one 1gb DDR2?

I wanna replace my factory 512mb 533Mhz to 1GB 667Mhz....or should i use factory 512mb 533Mhz + 1GB 667Mhz

and...how can I check my laptop to see if I am in Dual Channel mode ??


thanks

 

What Chipsets are those setups running?
I haven't really paid too much attention to hardware for a little while, so I'd like to brush up.
I've been googling and have only found so far the SiS655fx supporting 'flex memory'. But even in memory bandwidth benchmarks...the 'flex' setup falls behind true DC DDR. In gaming testing there didn't seem to be too much difference. (But we all know it's the benches that separate the men from the boys, right? )

http://www.sis.com/elibrary/elibrary_index03_000006.htm

... and I've seen mention about NForce chipsets supporting 3 modules of memory...but in that case it was a case of 2x256mb occupying one memory and then 1x512 occupying the second memory controller...in this case apparently you still should have mathching memory capacities.

and then as far as I know these aren't notebook chipsets.

 

You need two sticks of equal size to get symmetric dual channel. For other reasons it is best to get same make and model.

to go to 1GB symmetric dual channel, you can either

1. buy one additional 512MB 533 or 667, but system will clock to your original 533.

2. buy 2 512MB 667 for a total of 1gb

For asymmetric mode and 1.5GB (keeping your original 512MB) you could

1. get 1 GB stick 533 or 667, but system will clock to 533.

option 2 above is your only bet to get 1GB 667MHz in full symmetric dual channel mode, but as indicated above looser timings in currently available 667Mhz chips limit any real performance gain over 533 to around 5-10%, which may or may not be worth the $$ to you.

 

absurd,

the chipsets under discussion are Intel 945GM/PM and DDR2 memory, both are used in the E1505, which relates to the original question of this thread.

 

Basically in a very genralized nutshell from what I remember you could think of your stick(s) of memory like lanes of a highway. In Single channel mode your sticks would line up end to end forming 1 lane. In Dual channel mode your sticks would line up side by side forming 2 lanes. 2 lanes will get traffic to and from your CPU faster than 1 lane. Marketing would have you believe that you've doubled your speed (Didn't your mother ever tell you not to listen to marketers?), but in reality because traffic still has to break up into 2 lanes an then eventually have to remerge you wind up with maybe 15-20% more memory bandwidth. Because of this extra traffic break up and remerging it's reccomended that memory modules of the same brand and spec are used.

Dual Channel memory operation is a function of the Chipset. The Chipset is the hub that connects all of the data pathways from your CPU, Memory, Drives, Input/output devices. The chipset in your laptop is the Intel 945gm



As for seeing if you are operating in Single or Dual Channel mode...I notice that when I use CPU-Z http://www.cpuid.com/cpuz.php that it shows Dual mode for me (I have 2x512).

anyone else please feel free to chime in...

 

Yes, I know...I was wanting to know what chipsets were being used in the Screenshots that Drumfu referred to earlier. From everything that I've been googling on the 945gm I can't find any info to support Drumfu's claim of 'mixed memory' Dual DDR in the e1505. I've been trying to find out which chipsets do indeed support mixed DC operation and so far came up with the SiS and Nvidia only.

 

sorry, it's somewhere on this forum.

BIOS screenshots of mixed chips runing in dual channel confirmed.

EDIT:

found it. here's the BIOS screenshot

and

here's the thread where it came from

 

Hrm, I just took one of my 512mb ram out of slot B, was running 2x 512mb, still bios says I'm running Dual Channel. http://img137.imageshack.us/my.php?image=cimg0650medium6du.jpg

While CPU-Z seems to correctly reconize it.
http://img195.imageshack.us/my.php?image=cimg0651medium9km.jpg

 

Not doubting the BIOS screen shot it says what it is supposed to. Intel's own docs call that Dual Channel Asymmetric mode, so you still only access one channel at a time. If the channels are identical in size, then the system will do an overlapping access, initiating an access on the second channel before the first one is done. They call that Dual Channel Symmetric.

As long as both channels are populated, no matter what sizes, the system will always tell you it is dual channel.

Absurd: sorry for the confusion, thought you were asking me a question about the chipset.

 

This memory is backwards compatable, meaning you can put PC5400 memory in a mother board that was only designed to use up to PC5300 memory, you won't get the additional speed out of the PC5400 memory though by using it if your system is only capable of running at the PC5300 speed then that's the best it's going to run at. PC5300 and PC5400 are both DDR2 types of memory, you can't mix DDR with DDR2 memory, they are not compatable, DDR Memory started at PC1600 DDR and was produced all the way up to PC3200 DDR any system requiring DDR memory can run any memory in that range, even if your system was originaly designed for and came with DDR PC1600 in it. You will not be gaining anything though by taking your PC1600 memory out and replacing it with faster PC3200 memory if your board was only designed to handle the speed of the PC1600, then that's all the faster PC3200 is going to run in that board.

DDR PC3200 and DDR2 PC3200 are not inner compatable, at all, I note this because it could lead to some confusion for someone ordering new memory for a new or an older system. Some boards (no laptops I've ever seen) did come with 4 memory slots on the mother board which allowed you to use only DDR type memory in 2 of the slots, or DDR2 type memory in the other 2 slots, but you could not run a mix of DDR and DDR2 memory at the same time either 1 or 2 of the same in two slots one or 2 of the same in the other only, not all 4 slots filled and no mixing of DDR and DDR2 in any combination.

It's my understanding in looking at all the specs that for full DDR2 capabilities the 2 memory modules need to be of the same size (myself, I wouldn't mix the speed either). Backwards compatability was designed into this so the same memory would work on older systems, but without the current dual channel capability. It's also my understanding that for this same reason, installing mixed memory would work, but you would not be getting the true dual channel performance out of it. That I've based on rather cryptive design specs found at Intels web site and at some of the memory manufacturers web sites.

If you can get the full potential out of DDR2 on the newer motherboards while mixing memory sizes across the 2 slots I haven't seen anything out there that supports that yet. I'll of learned something new if someone could point me to any specs by any of the manufacturers that support that notion and it would be cool to know. It also certainly wouldn't be the first time limitations in design were released, but the world later found out could be achieved despite reports on it, the example I'm thinking of, on Intels web site, wasn't there an issue about this back when Intel tried shoving that garbage RAMBUS memory down our throats and people later learned other options would work, but the reports of this were never updated in Intels specs for the boards this affected?

Probably should also point out for memory shoppers, make sure you get the right type of memory for your laptop PC5300 memory for your laptop is different than PC5300 memory for your desktop and those 2 can not be mixed because the physical shape is different in order to fit with in the limited confines of your laptop. You would need SODIMM PC5300 or PC5400 for example for your laptop, fortuneatly for you though, it's more commonly refered to as just laptop memory when your out there shopping for it.

 

Just read your link here drumfu, certainly makes for some interesting reading and a lot of head scratching, but I still can't find any documentation or specs from anyone that supports it. I think there was another post in this thread here about a page back that references the simular data from the Intel web site that I was going off in my own conclusions.

Even after reading all that, it's just one of those things I don't think I could force myself to do, old habits I guess.