Thinkpads Forum

Not to start another argument about the second stick choice but I found this 2GB on Crucial site. Maybe it's been up and discussed already and I missed it. What do you think? Not concerned about pricing just good compatible stuff.

http://www.crucial.com/store/MPartspecs ... N=CT517023

Crucial Part Number: CT517023
Module Size: 2GB
Package: 200-pin SODIMM
Feature: DDR2 PC2-5300
Configuration: 256Meg x 64
DIMM Type: UNBUFFERED
Error Checking: NON-ECC
Speed: 667
SDRAM Timings: CL=5
Specs: DDR2 PC2-5300 • CL=5 • UNBUFFERED • NON-ECC • DDR2-667 • 1.8V • 256Meg x 64

Charlie, you found it! You've got Wonka's Golden Ticket!

Seriously, I've been looking for that 2GB stick...and haven't been able to find it until now (thanks). I even looked on Crucial's site last week...I wonder if they just released it...Everything else that I've found is always 2x1GB kits...now I'll have just what I need and the price is just right too, IMO!

Anybody know if there is any reason NOT to have a 1GB and a 2GB stick in my T60p? I don't see any reason to pay for another 2GB DIMM when the [censored] thing will only use 3GB anyway...and dual chan is no big deal as I understand it since the FSB is only 667Mhz....

BTW: I'll put the 2GB stick in the first slot and move the 1GB to the second slot...

EDIT: [censored]! When I tried to purchase said 2GB SODIMM here's what I got:

Part Availability Notice
We are sorry, but the product you selected is temporarily out of stock. However, we are constantly replenishing our inventory and there's a good chance that this product will become available soon. Check back often to see when the product you selected is available, or make your purchase today by returning to the previous page and selecting a comparable product. ..

I had a chat w/ sales no release date yet. If you remove the 1GB stick and replace with 2x-2GB it wil access the full 4GB at 667Mhz. That's what Crucial told me.

Hmmm. Kingston too but read the tech notes.

System Memory Configuration
Standard Memory: 512MB (Removable)

Maximum Memory: 2GB with current Kingston products
4GB with release of 2GB module

Expansion: 2 Sockets

CPU & Chip Set: Intel Core Solo Intel 945GM
Intel Core Duo Intel 945GM

Bus Architecture: PC Card
Manufacturer System PN: 2013-xxx; 2023-xxx

Technical Notes
If 4GB is installed, the recognized memory may be reduced to 3GB or less (depending on system configuration and memory allocation).

As you mentioned, this has been discussed at length in other threads. I've read some pretty good explanations about this and it seems that it is an Intel architectural limitation. I don't believe crucial and I think that Kingston is correct. 3GB is all you'll ever be able to use (all XP will see).

I can live with 3GB. I'll slap the new stick in and be a very happy camper indeed.

Price is down to $290.99 but still not available. Bummer

To clarify once and for all: Windows will only see 3GB max with a 32-bit system.

Also, what I've been told by Lenovo is that 3GB will only run at DDR2 533, due to limitations of the 945 chipset.

I only said I'd do the 1+2=3GB

According to Intel Dual-channel DDR2 667MHz Memory Support Up to 10.7 GB/s of bandwidth and up to 4GB memory addressability, for faster system responsiveness.

I'd believe the chipmaker anyway over some tech's response by Lenovo. They are feeding you a load from the OLD chipset and someone is pushing bad info.

See and clarify yourself.
http://www.intel.com/products/chipsets/945pm/index.htm

fbrdphreak wrote:To clarify once and for all: Windows will only see 3GB max with a 32-bit system.

Also, what I've been told by Lenovo is that 3GB will only run at DDR2 533, due to limitations of the 945 chipset.

jobes wrote:I only said I'd do the 1+2=3GB

According to Intel Dual-channel DDR2 667MHz Memory Support Up to 10.7 GB/s of bandwidth and up to 4GB memory addressability, for faster system responsiveness.

I'd believe the chipmaker anyway over some tech's response by Lenovo. They are feeding you a load from the OLD chipset and someone is pushing bad info.

See and clarify yourself.
http://www.intel.com/products/chipsets/945pm/index.htm

Perhaps instead of acting like a prick, you should ask where I got my information from or at the least check your source a little more carefully. I'd say the 533MHz limitation is probably more to do due with SODIMM memory certifications, since 2GB modules are relatively new anyway and 667MHz modules are new themselves.

But if you go to page 20 of the 945 datasheet, you will see this:

...currently validated at 533MHz only

I was told by Lenovo themselves, not a 1-800# tech, that 3GB is what is addressable in Windows (Which is common sense anyway for those who understand memory addressing) and that it will only work at 533MHz from Intel's side of the deal.

Thanks

I wasn't being a prick and if you cant handle a little countermatch... what ever. Get a life.

Yes you were. Moving on...

jeremivw wrote:As you mentioned, this has been discussed at length in other threads. I've read some pretty good explanations about this and it seems that it is an Intel architectural limitation. I don't believe crucial and I think that Kingston is correct. 3GB is all you'll ever be able to use (all XP will see).

I've never seen anyone say it's an Intel architectural limitation. Lenovo claims it's a limitation of 32bit PC architecture in general. But that's not correct. It depends on the particular motherboard. Some have more that 32 pins for the processor and can address up to 4Gb of RAM.

fbrdphreak wrote:To clarify once and for all: Windows will only see 3GB max with a 32-bit system.

Also, what I've been told by Lenovo is that 3GB will only run at DDR2 533, due to limitations of the 945 chipset.

That is not correct. This has nothing to do with Windows. Also, the claim about 533mhz I believe is a misperception of something Lenovo posted on it's website at one point and then retracted. Lenovo seemed to assert that since there are currently only 2Gb sodimms available in the 533mhz variety (an incorrect claim if Lenovo meant to make it), you would have to use one of those to have a 2Gb sodimm, and using a 533mhz sodimm would force all the memory on the system to clock out at that speed.

*

The question of whether or not 4Gb will be addressable on the T60, I think, remains unclear. It all depends on how Intel constructed the motherboards. Some 32bit systems can do it and others can't. As jobes points out, Intel claims on it's own web site that the boards in the T60 will address 4Gb.

These questions have been discussed at length in these threads:

http://forum.thinkpads.com/viewtopic.php?t=21025
http://forum.thinkpads.com/viewtopic.php?t=19012
http://forum.thinkpads.com/viewtopic.php?t=21389
http://forum.thinkpads.com/viewtopic.php?t=20186

Thanks donking for the great summary.

My mistake all, a 32-bit architecture can support 4GB. The number of pins to the processor really doesn't have anything to do with it IMO, its the size of the registers which determine addressability. 32-bit registers = 4GB RAM addressable, 64-bit registers = 8GB RAM addressable; at least in single processor systems.

The chipset supports 4GB @ 533MHz, its in the datasheet if you don't believe me. The question is will the Lenovo BIOS recognize two 2GB modules...the e-mail has been dispatched

Another correction. 64-bit address 2^64 bits of memory, that's ~20 billion GB.

For reference: 2^32 = 4.294967296 billion

fbrdphreak wrote:... 32-bit registers = 4GB RAM addressable, 64-bit registers = 8GB RAM addressable; at least in single processor systems....

onix wrote:Another correction. 64-bit address 2^64 bits of memory, that's ~20 billion GB.

For reference: 2^32 = 4.294967296 billion

haha, doh. Brain needs to stop farting...

OK let me see if this makes sense:

Windows XP Professional can support 4GB physical memory. However it cannot allocate more than 3GB memory per 32-bit process, and only if a special switch is used in boot.ini; 2GB is default. XP supports 4GB virtual address space, so while it seems as though you will be able to use all 4GB of RAM a single thread cannot address more than 3GB of it. Hunky dory now?

http://support.microsoft.com/kb/888732/en-us

People really should look at this thread, which covers the whole Windows and 32 bit questions:

http://forum.thinkpads.com/viewtopic.php?t=19012

As BrianR says there, the 3Gb switch is a red herring. Windows XP supports 4Gb of physical memory. The switch thing is only about how much virtual address space a program can have.

People should also really really read the article that BrianR refers people to:

http://www.interact-sw.co.uk/iangblog/2 ... s3gbenough

The 4Gb question does have to do with how many pins there are for the processor. Some of the pins are used for the PCI bus and some for the system bus. If there are only 32 pins, you only have 32 bits of addressable bus space, some has to be shared with the PCI bus, and that limits the memory to less than 4Gb. But some motherboards have more pins and can get around this problem. In fact, the article points out, that some 32-bit CPUs have 36 pins for physical addressing and can in theory address 64Gb of physical address space.

Anyway, if that's not clear, read the article. It's very well written.

Lastly, I'm still not convinced about the 533Mhz thing. As fbrdphreak points out, the data sheet for the Intel chipset says "4Gb currently validated at 533 MHz only." So doesn't that mean that Intel has not tested 4Gb of 667MHz memory on the chipset? It doesn't mean that 4Gb of 667MHz memory will force the chipset to run at 533MHz, I don't think.

jobes wrote:I had a chat w/ sales no release date yet.

I emailed Crucial and they emailed back and said the release date for the 2Gb sodimm is 3/31. Hope that turns out to be true.

donking! wrote:It doesn't mean that 4Gb of 667MHz memory will force the chipset to run at 533MHz, I don't think.

If the BIOS says to do so, it certainly will. And given the lack of certification in those sticks, I'd say its a good possibility.

fbrdphreak wrote:

donking! wrote:It doesn't mean that 4Gb of 667MHz memory will force the chipset to run at 533MHz, I don't think.

If the BIOS says to do so, it certainly will. And given the lack of certification in those sticks, I'd say its a good possibility.

So if Intel hasn't tested 667MHz memory yet on the 945 chipset, they'll set the BIOS to run at 533MHz if there's 3Gb of memory (but at 667MHz with 2Gb or less)? I'm not saying that's not correct. But that seems really weird. Why would they do that?

Fortunately Crucial has a 30-Day return policy. I'll probably just buy the sodimms and settle the question for myself. (And also the 4Gb question.) Actually, how would I tell once the sodimms are in there what clock speed the memory is operating at?

donking! wrote:So if Intel hasn't tested 667MHz memory yet on the 945 chipset, they'll set the BIOS to run at 533MHz if there's 3Gb of memory (but at 667MHz with 2Gb or less)? I'm not saying that's not correct. But that seems really weird. Why would they do that?

Fortunately Crucial has a 30-Day return policy. I'll probably just buy the sodimms and settle the question for myself. (And also the 4Gb question.) Actually, how would I tell once the sodimms are in there what clock speed the memory is operating at?

Well Intel doesn't set the BIOS; the manufacturer does. I'm 99% sure Lenovo has already set the Napa-based Thinkpads BIOS' to downclock to 533MHz, even if the chipset might support it. They told me once already, I just can't find the e-mail...

Other mfrs do it all the time. MSI forces the chipset in their MS-1029 notebook (An ATI RS480 chipset, uses DDR RAM & AMD CPU's) to downlock 2x1GB DDR400 RAM to DDR333 for stability reasons. High density SODIMM's just arent' as stable to clock as high.

I have another queston: Does it necessarily matter if the memory clocks down to 533MHz? At least with two identical 2Gb sodimms. Then wouldn't I get the dual channel effect? That would exceed the 667MHz speed of the frontside bus anyway? In either case, it seems like the 667MHz frontside bus is the real limitation.

donking! wrote:I have another queston: Does it necessarily matter if the memory clocks down to 533MHz? At least with two identical 2Gb sodimms. Then wouldn't I get the dual channel effect? That would exceed the 667MHz speed of the frontside bus anyway? In either case, it seems like the 667MHz frontside bus is the real limitation.

It won't make a huge difference. In terms of actually performance, the only place you will probly see a difference is in Photoshop and maybe some video/audio encoding. Even games won't benefit. If you think about it, most of your daily activities don't saturate the front side bus. MS Office, AV, etc don't max out the FSB or RAM anyway so a 20% drop in mem clock won't matter much for most things. And keeping it in dual channel increases the number of channels it can transmit data on, so while keeping the same clock you can transmit more data than with single channel. Think of it like a highway going from two lanes to four lanes; same speed limit, more cars.

Anyway, no its not a big deal. If you want 3-4GB, get the 2x2GB DDR2667 sticks and be happy But if you can find DDR2 533 2GB sticks get those to save the money.

Hey fbrdphreak, thanks for the further thoughts on the matter. Photoshop (and maybe some video editing) is the reason I want all this memory. Otherwise I'm sure I'd be happy with 2Gb.

I realize I'm probably splitting hairs. I'm more just curious to understand it now. But I thought the frontside bus is a bottleneck of sorts.

Using your analogy of the two lane highway. I thought it was two lanes coming out of the memory. But both lanes feed into the frontside bus. So whatever the bandwidth of the frontside bus, that limits how fast data can be transferred from and to memory. In other words, the dual channel memory adds a channel going into the frontside bus, but it doesn't double the bandwidth of the frontside bus itself.

So whether its two 2Gb sodimms at 533Mhz in dual channel mode or two 667Mhz sodimms in dual channel mode, they're going to be limited by the 667Mhz bandwidth of the frontside bus and both effectively end up running at the same speed. Only forcing the memory to run in single channel mode at 533Mhz or 667Mhz would come in under the full bandwidth of the frontside bus.

I was looking at this article:

Intel Dual-Channel DDR Memory Architecture White Paper HTML Version
Intel Dual-Channel DDR Memory Architecture White Paper PDF Version

I guess I don't get it. If crucial is selling 2 gb memory that supports 667, and there is stability issues with the ram, wouldn't one say that the memory is faulty? After all it is not meeting the speed rating that is claimed.

The only reason I can see downgrading the speed is from a heat perspective, larger, dense chips create more heat, which can't be disposed of correctly.

So from what you are saying the 667 speed is supported by 1 gb modules and lower, and for over 1gb, only 553 is supported. This latter constraint is imposed by the computer manufacture although both the cpu and memory manfactures support the 667 speed.

As far as using 2 2GB sticks. I understand that may be done, but in that case bios will mask some of that address space out. These addresses are used for pci and such. So it almost guarantee that windows will see less than 4GB of memory, but does any one know how much less. I have seen other motherboards that show anywhere from 3.2 GB to 3.5, from within windows when 4 GB is installed (i.e. the missing amount is due to bios reserving that address space).

Does anyone know how much the t60 bios will reserve?

Then the next question I see is with the virtual size of a program within windows, which is limited to 4 GB. Normally that is split into 2 2GB (user and kernel address space). The 3GB option mention switches that alignment to be 3 GB user, 1 GB kernel. So this is limit is per process.

Windows itself supports a larger address space since different programs can be running, on one system I have 8GB of virtual address space, so the total of all processes needs to be less than 8 gb.

So I was wanting to verify that the I can reduce swapping of processes by increasing the system ram to 4gb (and seeing what part of that is actually visiable and usable by windows), so that I can run multiple large image processes.

deforest wrote:...bios will mask some of that address space out. These addresses are used for pci and such. So it almost guarantee that windows will see less than 4GB of memory...

...So I was wanting to verify that the I can reduce swapping of processes by increasing the system ram to 4gb (and seeing what part of that is actually visiable and usable by windows)...

Can I recommend for the third time in this thread that people read the following article:

http://www.interact-sw.co.uk/iangblog/2 ... s3gbenough

There is no certainty, or "guarantee," at all that windows will see less than 4Gb of memory. It all depends on how Intel designed the motherboard. If there are more than 32 pins for the processor, then there will be plenty of extra address space for the pci bus, etc., and it won't get in the way of using all 4Gb of RAM. Intel claims the 945PM chipset can address 4Gb of RAM, so hopefully it should work despite Lenovo's claims to the contrary. But people do so many different things with motherboard designs, it's hard to really know until one of us tries plugging 4Gb into a T60.

The article explains this very clearly.

Crucial is a very reputable memory maker. If they claim a certain sized stick of theirs will work, it will work. If not they will refund your money, provided you get the stick directly from them.

Price is now at $318, but still not available to order.