4GB memory

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period3 · #1 Post by **period3** » Wed Oct 24, 2007 4:39 pm

Hi all,

I have a T60 C4U-2007 with 2 gigabytes of memory and a 2GHz T2500 processor.

I would like to upgrade to 4 GB of memory, but my understanding is that T60's do not support 4GB of memory. Questions:

- If I upgrade my processor to core 2, I will still not be able to use 4GB of memory, correct?

- If I upgrade to 3GB of memory using a 2GB sodimm and a 1GB sodimm, I'll be running in single channel mode. If I upgrade to 3GB of memory using two 2GB sodimms then I'll be in dual channel mode - even though I can't access all 4GB. Correct?

- If I buy a new thinkpad, how do I know whether it supports 4GB of memory? Do all T61 models support 4GB? Do any T60's support 4GB?
The lenovo site says 4GB in some places and 3GB in others. Very confusing.

As an aside, is anyone aware of a notebook that supports 8GB of memory? According to intel, their Centrino pro chipset supports up to 8GB, but I don't see any notebooks that do (I guess they'd need 4 SODIMM slots)....

I only use Linux, and all the applications I use have 64 bit versions available.

Thanks

#2 Post by **erik** » Wed Oct 24, 2007 4:55 pm

none of the socket M thinkpads (T60/T60p) can support more than 3GB no matter what chipset is used. you need a socket P thinkpad (T61 or T61p) for 4GB support.

forget about dual channel. it's not worth the extra cost and to my knowledge no one has ever proven that 4GB in a 3GB-capable thinkpad makes any difference whatsoever.

8GB total memory might be supported with the current line of socket-P-processor-based thinkpads. the bigger limitation is the fact that no 4GB DDR2-667 SODIMMs exist, not the number of slots. if and when these modules are released, we'll soon know whether they are supported in the T61/T61p or not.

Mr Blek · #3 Post by **Mr Blek** » Wed Oct 24, 2007 5:18 pm

Its possible to upgrade the processor on a T60p? Are they not soldered in?

period3 · #4 Post by **period3** » Wed Oct 24, 2007 6:45 pm

Nope, they're socketed and should be upgradeable.

Mr Blek wrote:Its possible to upgrade the processor on a T60p? Are they not soldered in?

brentpresley · #5 Post by **brentpresley** » Wed Oct 24, 2007 8:20 pm

Mr Blek wrote:Its possible to upgrade the processor on a T60p? Are they not soldered in?

They are VERY upgradeable.

See my sig for the fastest available config for a T60p.

#6 Post by **bill bolton** » Wed Oct 24, 2007 8:26 pm

Read the stickied thread in this forum for information of using 4GB...

http://forum.thinkpads.com/viewtopic.php?t=49703

Cheers,

Bill B.

#7 Post by **erik** » Wed Oct 24, 2007 10:25 pm

bill bolton wrote:Read the stickied thread in this forum for information of using 4GB...

http://forum.thinkpads.com/viewtopic.php?t=49703

Cheers,

Bill B.

we should unlock that thread so i can update it with info on T60/p systems. i can write up some info to encompass both 3GB-capable and 4GB-capable sytems.

update: bill unlocked the thread and i updated it to include info on the T60/p 945GM and 945PM chipsets and their limitation to 3GB total physical memory. hopefully that covers most memory questions in the future.

thanks bill!

whizkid · #8 Post by **whizkid** » Thu Oct 25, 2007 1:29 pm

erik wrote:forget about dual channel. it's not worth the extra cost and to my knowledge no one has ever proven that 4GB in a 3GB-capable thinkpad makes any difference whatsoever.

The first part of that statement is a value judgment and not a fact. The second part is just plain wrong in that memory benchmarks do show improvement when using dual-channel mode.

If money is no object, extra cost is close enough to zero. If you spend time waiting for computations that computes to a dollar value, breakeven should be easy to compute.

4GB in a 3GB machine will provide dual-channel support, which is about 10% faster on memory-bound processes, of which there are not many. (Compiles? Simple image and video transformations?)

Hmm. Let's compute: Say you spend your days doing this kind of work, and actually wait for the machine two hours a day. Current prices from Crucial show a 1GB (DDR2, PC5300) stick is $30, and a 2GB stick is $100. So if you (for example) bill $50 an hour, you can do 10% more work per hour, or around $5 per hour, and the chip pays for itself in 14 hours, or seven work days. The rest is gravy.

Upgrading the CPU to Core 2 even at the same clock speed will also improve performance, and you can put in a Core 2 Duo at 2.33GHz if you really want to save time.

(Then again, if you have this kind of work, a 16-core workstation will also pay for itself.)

#9 Post by **erik** » Thu Oct 25, 2007 1:46 pm

erik wrote:forget about dual channel. it's not worth the extra cost and to my knowledge no one has ever proven that 4GB in a 3GB-capable thinkpad makes any difference whatsoever.

whizkid wrote:4GB in a 3GB machine will provide dual-channel support, which is about 10% faster on memory-bound processes, of which there are not many. (Compiles? Simple image and video transformations?)

with all due respect, you missed the point of my statement. i have never seen a definitive test on an intel 945GM/945PM-based T60/p thinkpad showing that 4GB in dual-channel mode makes any difference whatsoever. the supposed "10% gain" is anecdotal at best and words alone are not enough for me to buy into the hype. please show me some evidence backing up this claim, especially on a T60 or T60p. i would appreciate seeing the results and learning from them.

whizkid · #10 Post by **whizkid** » Thu Oct 25, 2007 2:19 pm

I do not doubt that you haven't seen evidence. However, I have run memory benchmarks myself on 1GB vs. 2GB to show dual-channel on the T60 is supported, and posted them on this forum, as have others. I got about a 12% improvement, IIRC. You're welcome to review my posts.

I also don't doubt that 3GB vs. 4GB will show the same improvement for a second, but you seem to have that doubt. Is a single test of a lone T60 evidence, or is that another anecdote, or just words alone?

I'd be happy to run the benchmarks myself if someone will lend me the chips.

#11 Post by **erik** » Thu Oct 25, 2007 2:33 pm

i'm not doubting dual-channel support, my doubt is that 4GB will show any appreciable improvement over 3GB in any real-world benchmark tests -- not just memory tests. if this 10~12% gain is true then it should be noticeable in benchmark tests and be worth the extra $100 investment for T60/p owners. however, if benchmarks show no appreciable differences then i fail to see why there's a big argument here.

if you've run tests proving the above then please post some links. my intent here is to learn, not to argue. if definitive, hard evidence supporting the benefit of 4GB in a 3GB-limited thinkpad then i will add the information to my sticky for others to learn, too.

#12 Post by **bill bolton** » Thu Oct 25, 2007 6:35 pm

whizkid wrote:4GB in a 3GB machine will provide dual-channel support, which is about 10% faster on memory-bound processes, of which there are not many. (Compiles? Simple image and video transformations?)

Any dual channel benefits are only realisable when the amount of actually addressable memory in both channels is identical.

In the case of a T60 it is physically impossible to have a 3GB memory configuration with identical addressable amounts of memory in each channel, due to the addressing limitations in the hardware platform, so the benefit of dual channel is lost.

Any dual channel benefits are only realisable in a T60 with 2 x 512MB or 2 x 1Gb memory card installations.

Cheers,

Bill B.

mikesugar · #13 Post by **mikesugar** » Thu Jul 31, 2008 11:14 am

I know this question has been covered, but I have a question that does not appear to have been covered.

I have a T60 model 8741 4BU. I installed 4GB.

In Windows, only 3GB shows up. But when booting, all 4GB show up in the BIOS.

Based on other posts, I thought it was a hardware limitation that stopped my T60 at 3GB and PAE would not work for me.

But since the hardware can apparently see all 4GB, I am wondering if there is a light at the end of the tunnel and I may be able to get all 4GB in Widows (XP32 SP2 by the way).

If anyone can shed any light, please do.

Thanks in advance.

Mike

#14 Post by **erik** » Thu Jul 31, 2008 11:26 am

mike, the BIOS reports 4GB because you have 4GB physically installed. the chipset can see that last 1GB but cannot address it—and that's the crux of the situation. memory is only useful if it's addressable.

mikesugar · #15 Post by **mikesugar** » Thu Jul 31, 2008 11:57 am

Thanks

4GB memory

4GB memory

upgrade is possible.

4GB on a T60 (8741 4BU)

Thanks

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