Thinkpads Forum

Folks,

I have searched and found several related topics, but none provided a definite answer. I apologize if this will be considered a duplicate.

I am about to buy x61 Intel® Core™ 2 Duo L7700 LV and will load it with XP Pro (having heard and read nightmarish stories....). I understand XP recognizes up to 3GB. I also read about the dual channel related improved performance. Putting cost aside, which configuration would result in a better performance:

2 GB PC2-5300 DDR2 SDRAM 667MHz SODIMM Memory (2 DIMM)
3 GB PC2-5300 DDR2 SDRAM 667MHz SODIMM Memory (2 DIMM)

Does the 3GB configuration enjoy the dual channel advantage?

thanks in advance.

Why not just go for 4GB? I bought 2 sticks of 2GB OCZ for $50 each. There'll be more sales like that, so I'd hold off.

chait wrote:Does the 3GB configuration enjoy the dual channel advantage?

no, but i seriously doubt you'd ever notice the difference between single- and dual-channel in real-world situations.   dual-channel's benefit is only about 5~8% on memory-intensive tasks.

Having checked lots of potential sources but where did you find that sale price of 50 dollars on the OCZ 2GB memory sticks for your X61s.?
Would 4 gigs of ram over my current 2gb's really yield improvement on processor intensive programs like PS CS3. I am very happy with my new 61s and even Vista Biz is running better than I feared. I'm missing XP less and less. This is my first IBM/Lenovo and it's tops.

nyp797 wrote:Would 4 gigs of ram over my current 2gb's really yield improvement on processor intensive programs like PS CS3.

3~4GB will help photoshop run better.   you'll have to use a 36- or 64-bit OS to fully utilize 4GB since vista/XP 32 can only address 3GB.

see this thread for more info as it also applies to the X61-series: http://forum.thinkpads.com/viewtopic.php?t=49703

Thanks, I was rather aware of the recognition factor of 32 & 64bit Vista versions. So, just adding a single 2gb ram module would give me the 3gb limit. Other than the Lenovo OEM OCZ branded modules, are there suggestions for other brands absolutely known to work in the X61s series. Certainly Crucial, Kingston, et al are all good but I'd appreciate the views of owners who've gone with brands other than OCZ that worked with issues.

Has anyone actually measured the difference in power draw with 4GB as opposed to 2GB? I don't care about the extra $100 - but I'd hate to lose battery life. The other downside is that hibernation times (on and off) double.

Cheapest one on newegg currently is $39.99 shipped

http://www.newegg.com/Product/ProductLi ... 6&name=2GB

You may find them to be even cheaper if you wait around for rebate and look around other retailers such as buy.com, zipzoomfly.com, fry's etc. Earlier I bought a pair of 2GB (i.e. 4GB) from fry's for $65 after rebate.

The low prices of ram these days really surprised me. If you are going to 3GB, I don't see the reason of why not spending just a little bit more to get 4GB.

Nice deal
I bought the OCZ from NCIX.com during their black Friday sale. They have a new sale every week. It's like a "Newegg" for Canada (but they do also have a US site). It's no Newegg (they don't ship to Canada FYI) but they still have great deals.

As for power drain - I've noticed no such thing. In fact, I seem to get better battery life now (I got more than 9 hours on my 8-cell when I was just going over notes on OneNote2007 with minimum settings). RAM doesn't use very much power.

I'd still recommend 4GB to future-proof. I'm upgrading to a dual-boot Vista 64-bit SPI / Kubunto or SuSE 64-bit during the Christmas holiday.

One thing about OCZ though... I am sure their memory products are great,I have hear many story that many of their rebates were rejected by OCZ for no reason. If you dig around newegg reviews, you should be able to find some comments regarding their rebates too.

erik wrote:

chait wrote:Does the 3GB configuration enjoy the dual channel advantage?

no, but i seriously doubt you'd ever notice the difference between single- and dual-channel in real-world situations.   dual-channel's benefit is only about 5~8% on memory-intensive tasks.

The GM965 chipset used in X61 supports the Intel Flex Memory which in turn "gives users a more flexible memory upgrade option by allowing different memory sizes to be installed while maintaining dual-channel mode/performance."

Not sure about the performance difference between using asymmetric and symmetric pairs of memory through. You may search the Net for more information.

Anyway, I'll take the 3GB over the 2GB option if money is not concerned. More memory probably has a greater effect on the bandwidth in this case.

I've bought nothing but OCZ for a while now, because they always have rebates on them.

I've gotten the rebate cheques 2/2 times so far

Just bought another 2, so I'm waiting on another 2 cheques. Takes about 2 months, but you do get your money back.

OK - I answered my own question.

I bought 2x2GB OCZ ($99 frys) for my X61s. Took out the 2x1GB Hynix sticks that IBM supplied.

Power consumption is pretty much unchanged. About 8.5W idle with the screen on - no wi-fi. About 6.3W idle with the display off. Within .1W of what I got with the old DRAM.

Your mileage may vary - different DRAM have different power consumption - but for me it looks like no loss to go to 4GB (I only get 3GB after video ram with XP-pro)

Good stuff.
Enjoy

On this topic,

I bought a X61s 7668 type machine; spec says 800 MHz FSB; the machine has two memory sticks

labelled pc2-5300c-555-12-E0

which seems to be DDR2-667 MHz memory.

Is that correct? Can this machine run faster memory?

thanks for a note,
Gerd

gerdh wrote:which seems to be DDR2-667 MHz memory.

Is that correct? Can this machine run faster memory?

yes, that's correct.   it can run 800MHz modules but they will downclock to 667MHz because the chipset limits the memory bus to 667.

erik wrote:

gerdh wrote:which seems to be DDR2-667 MHz memory.

Is that correct? Can this machine run faster memory?

yes, that's correct.   it can run 800MHz modules but they will downclock to 667MHz because the chipset limits the memory bus to 667.

Are you sure about that? If the chipset is allowing the processor to use 800FSB (X61s not X61) then why would it limit the memory to 667? Dosen't that defeat the purpose in have a CPU with 800FSB?

I just ordered the 1.8 C2D LV with 800FSB and I'm looking for memory for it.

DRAM is dual channel - so 400MHz is enough to supply the CPU - the rest is for graphics and I/O.

awolfe63 wrote:DRAM is dual channel - so 400MHz is enough to supply the CPU - the rest is for graphics and I/O.

You lost me there. What does that have to do with 800MHZ Ram not working on a laptop with an FSB of 800Mhz?

it does work, but the extra speed cannot be utilized as the CPU has only one channel, but the Ram can respond with two channels.
So you will not see any performance gain if you go higher than 530 Mhz Ram which is good enough.

Roughly. The full story is a bit more complex (RAS/CAS timing, latency, burst mode, etc)

erik wrote:

gerdh wrote:which seems to be DDR2-667 MHz memory.

Is that correct? Can this machine run faster memory?

yes, that's correct. it can run 800MHz modules but they will downclock to 667MHz because the chipset limits the memory bus to 667.

no

Edit: I rechecked this, and you're right (sorry for my "no"). The Memory controller of Santa Rosa does only support up to 667 Mhz. 800 Mhz Ram seemingly will run at 667 Mhz then. Anyway these Ram clocks are not linked to FSB clock and RAM/CPU interface works asynchronously (data transfers are not in sync).

So for sure then, it is pointless to purchase 800MHZ laptop memory? Why would they even make that memory then?

Why does the CPU specification specificaly 800MHZ if it only runs at 400MHZ?

The CPU runs 64-bits at 800MHz. The DRAM runs at 64 or 128 bits (1 SO-DIMM or 2) at 667MHz.

Faster SO-DIMMS are for other chipsets. For example, the latest Turion 64 X2.

awolfe63 wrote:The CPU runs 64-bits at 800MHz. The DRAM runs at 64 or 128 bits (1 SO-DIMM or 2) at 667MHz.

Faster SO-DIMMS are for other chipsets. For example, the latest Turion 64 X2.

Bummer I thought I was getting faster performance with 800FSB...

Thats Kinda lame them since your pretty much restricted by the memory (bottlenecked)...

FSB remains the bottleneck, it is single channel (64 bit) and interfaces the CPU and the Ram. And that is why FSB800 is faster than FSB667. But RAM is dual channel, and fast enough if you plug in 530 Mhz chips.

So I need to look for 530 or 667mhz ram as the OP seems to be getting mixed responses.

Does it matter which MB you have (X61 or X61S?)

Justintoxicated wrote:So I need to look for 530 or 667mhz ram as the OP seems to be getting mixed responses.

yes, any of 530,667 or 800 will work and will provide same performance. But you need to get the same timing as the one built in to have dual channel working as fast as possible (unless you do not want to reuse it). Also different Ras/Cas timing can interfere and may result in some 5-10% performance impact, so best choice is to get exactly the same module again, or at least the same brand.

Does it matter which MB you have (X61 or X61S?)

These both have same chipset, so does not matter. x60 is another story. As far as I know this does not provide asymetric dual channel (e.g. 1GB+2GB). Santa Rosa chipset does support it and therefor 1GB (original)+2GB is a good choice.

pibach wrote:

Justintoxicated wrote:So I need to look for 530 or 667mhz ram as the OP seems to be getting mixed responses.

yes, any of 530,667 or 800 will work and will provide same performance. But you need to get the same timing as the one built in to have dual channel working as fast as possible (unless you do not want to reuse it). Also different Ras/Cas timing can interfere and may result in some 5-10% performance impact, so best choice is to get exactly the same module again, or at least the same brand.

Does it matter which MB you have (X61 or X61S?)

These both have same chipset, so does not matter. x60 is another story. As far as I know this does not provide asymetric dual channel (e.g. 1GB+2GB). Santa Rosa chipset does support it and therefor 1GB (original)+2GB is a good choice.

Well it appears most 533 hmz memory is C4 while most 667 is C5... Will the C5 667 run at C4 speeds if I plug it into this laptop? I'm not going to assume this as it is not always the case.

Unfortunately Lenovo wants about 4x as much for 4GB as purchasing it elsewhere online, so it would make more sense to purchase 2 new sticks and toss the 1GB stick in the trash that it came with.

Same goes for the 80GB Hard drive...

I wish I could have save another $100 and got the laptop with no memory and no Hard drive...

If you buy 2 same new modules the timing will not interfere and you get full dual channel speed, thus should be always fast enough to fully utilize FSB800. There is some slight probabililty that bad timing might interfere with FSB800 clocks and Ram speed de facto gets below 400 Mhz with a slight deterioration in performance. To answer it more precisely, one need to calculate the exact timing behavior which can be quite complex.

So I would suggest you buy 667 MHz from Kingston or other reputable brand, this will surely work at full performance and does not cost much more than the slower 533 Mhz Ram.

Anyway, you will rarely notice any performance difference, as FSB800 usually will not be fully utilized by an application.

pibach wrote:If you buy 2 same new modules the timing will not interfere and you get full dual channel speed, thus should be always fast enough to fully utilize FSB800. There is some slight probabililty that bad timing might interfere with FSB800 clocks and Ram speed de facto gets below 400 Mhz with a slight deterioration in performance. To answer it more precisely, one need to calculate the exact timing behavior which can be quite complex.

So I would suggest you buy 667 MHz from Kingston or other reputable brand, this will surely work at full performance and does not cost much more than the slower 533 Mhz Ram.

Anyway, you will rarely notice any performance difference, as FSB800 usually will not be fully utilized by an application.

If the 667MHZ ram is only going to run a 533 anyways, would it not be better to get C4 533 rather than C5 667...C4 should be significantly faster than C5 since the ram will not run at 667 anyways?