Thinkpads Forum

What is the maximum amount of RAM for the X60s? The information on the Lenovo site is conflicting. The ThinkPad notebooks overview page says that the X series can have up to 4 GB RAM. In contrast, a page that shows the X60 and X60s says that both models can have up to 2 GB RAM. Which information is correct?

the maximum the machine can use is 3GB, however in order to have 3 GB you need to install 2GBX2 stick, ie total 4 GB ram

Why would they even do something like that? It doesn't seem to make any sense. Can't 4GB be 4GB?

rkuo wrote:Why would they even do something like that? It doesn't seem to make any sense. Can't 4GB be 4GB?

It's...complicated. Windows XP can use, in total, 3GB (even with a kludge in the boot to let it use an extra 3GB on top of 2GB). The chipset supports 4GB; other OSes, however, can utilize the total of 4GB.

christopher_wolf wrote:

rkuo wrote:Why would they even do something like that? It doesn't seem to make any sense. Can't 4GB be 4GB?

It's...complicated. Windows XP can use, in total, 3GB (even with a kludge in the boot to let it use an extra 3GB on top of 2GB). The chipset supports 4GB; other OSes, however, can utilize the total of 4GB.

I'm not sure that's correct. My understanding is that, with the Core Duo being a 32-bit CPU, it can only address 4GB of RAM. But the addresses near the top are used by the CPU to "talk" to other parts of the system, like PCI devices, the BIOS, and the AGP aperture. So this is not a software limitation, but a hardware one. You can still put 4GB of RAM in any system that supports it, but the CPU won't be able to address all of it.

I cannot speak for the other OS's, but I know that Linux has the same problem reporting 4GB RAM as something smaller.

My desktop has a 3.2ghz Pentium 4 (Northwood) with an Intel D875pbz motherboard and 4GB of RAM. In the BIOS, the memory size reported is 4096MB (4GB). However, when I turn the system on, during POST, it reports a memory size of 3584MB (3.5GB). When I look under My Computer->Properties, XP reports it as 3.5GB as well. I had put on Slackware Linux 10.2 for experimenting, and it reported about 3.5 million KB (which is ~3.5GB).

And no, there is no way for one to claim the addresses back so that the CPU can address all 4GB of RAM.

I am curious about one thing with regards to the X60 (and the T60, I suppose). I, too, read conflicting info about the maximum RAM these ThinkPads support. I wonder how much RAM will be reported if one sticks in 4GB. See, the amount of addresses that the CPU needs will vary, meaning that the computer may not report the installed RAM as 3.5GB; it could be lower. I wonder if the ThinkPads will report 4GB RAM as 3.5GB, or higher, or lower, even as low as 3GB (which is why I think some sites state that the maximum RAM allowed is 3GB).


69

The processor is 32bit, but indeed the memory limit of the processor has been 64GB for many years. The maxium memory supported by a computer is decided by the design of motherboard. And the acutual memory application can use also depends on the operating system.

Duo Secundus wrote:

christopher_wolf wrote: It's...complicated. Windows XP can use, in total, 3GB (even with a kludge in the boot to let it use an extra 3GB on top of 2GB). The chipset supports 4GB; other OSes, however, can utilize the total of 4GB.

I'm not sure that's correct. My understanding is that, with the Core Duo being a 32-bit CPU, it can only address 4GB of RAM. But the addresses near the top are used by the CPU to "talk" to other parts of the system, like PCI devices, the BIOS, and the AGP aperture. So this is not a software limitation, but a hardware one. You can still put 4GB of RAM in any system that supports it, but the CPU won't be able to address all of it.

I cannot speak for the other OS's, but I know that Linux has the same problem reporting 4GB RAM as something smaller.

My desktop has a 3.2ghz Pentium 4 (Northwood) with an Intel D875pbz motherboard and 4GB of RAM. In the BIOS, the memory size reported is 4096MB (4GB). However, when I turn the system on, during POST, it reports a memory size of 3584MB (3.5GB). When I look under My Computer->Properties, XP reports it as 3.5GB as well. I had put on Slackware Linux 10.2 for experimenting, and it reported about 3.5 million KB (which is ~3.5GB).

And no, there is no way for one to claim the addresses back so that the CPU can address all 4GB of RAM.

I am curious about one thing with regards to the X60 (and the T60, I suppose). I, too, read conflicting info about the maximum RAM these ThinkPads support. I wonder how much RAM will be reported if one sticks in 4GB. See, the amount of addresses that the CPU needs will vary, meaning that the computer may not report the installed RAM as 3.5GB; it could be lower. I wonder if the ThinkPads will report 4GB RAM as 3.5GB, or higher, or lower, even as low as 3GB (which is why I think some sites state that the maximum RAM allowed is 3GB).


69

Perhaps there is some confusion as to the definition of available memory versus addressable memory.

Windows will split, in Virtual Memory (not to be confused with swap space), into two partitions (this is alot like disk management, in fact, IBM's JFS is actually based on a memory manager). 2GB get allocated for the kernel and then another 2GB get allocated for the application out of a total of 2^32= 4.2 billion. The 3GB and, on Windows 2003, 4GT "cheats" simply allow for more VM addressing to expand it to 4GB. This spawns other limitations set on Windows, but they don't have to do with the CPU. A 32-bit x86 CPU *without PAE* can only address 4GB.

With \PAE (Physical Address Extension) can support up to, as stated above, 64GB of memory. Windows, however, could not possibly use more than 3GB if it was based on the 2000 Architecture or 4GB if it was based off the 2003 version with all the proper boot switches set.

Any other OS running on, say, an Intel x86 could, without being limited by the motherboard or any other similar hardware restrictions, address 64GB of memory with the CPU without a problem if PAE is supported. PAE has been supported since the Pentium Pro and is further documented in a pretty nice book by Solomon and Russinovich. There *are* versions of the 2003 kernel available with a PAE boot switch.

Some hardware, like PCI Express, do indeed reserve a portion of the memory for themselves; usually, you will see 3.24GB out of 4GB on Windows XP if that is the case. This is only an issue on Windows 2000 and derived (therefore, Windows XP and Windows Home) operating systems and really only because you won't be able to get it to "see" more than 4GB of memory. Other OSes, however, still have to deal with the PCI Express taking up some memory, but depending on their kernel, they can access up to 64GB with PAE on an x86 CPU that supports it. Meaning that they *can* go to and past the 4GB limit; at which point, the ~1GB or so of memory and bandwidth reserved for something like the PCI express or other dedidated hardware becomes rather trivial.

HTH

To summarize the discussion, the X60s may be able to use up to 4 GB RAM, depending on the operating system, but with Windows XP the usable amount of RAM is limited to 3 GB. Is this correct?

Does anyone know if/where 2GB memory SIMMS are available for this notebook? Crucial doesn't list any...

-Todd

FredFromNYC wrote:To summarize the discussion, the X60s may be able to use up to 4 GB RAM, depending on the operating system, but with Windows XP the usable amount of RAM is limited to 3 GB. Is this correct?

Correct, the amount available will be around ~3.24GB or so on Windows XP; this will change going from OS to OS.

laughingtonto wrote:Does anyone know if/where 2GB memory SIMMS are available for this notebook? Crucial doesn't list any...

The X60 uses PC2-5300 type memory, the same as the T60/ps use. There are 2GB PC2-5300 sticks available for the T60; search the T60 forum and you will come up with a few threads that talk about them.

Is there any need to match a 2GB simm to a 2GB simm? Since I can only access a little over 3GB total, would a 2GB + a 1 GB simm work?

-Todd

laughingtonto wrote:Is there any need to match a 2GB simm to a 2GB simm? Since I can only access a little over 3GB total, would a 2GB + a 1 GB simm work?

-Todd

That should work, discussion of Dual-Channel mode aside. If I was going to get a 2GB stick, I would just go all the way and get two.

FredFromNYC wrote:To summarize the discussion, the X60s may be able to use up to 4 GB RAM, depending on the operating system, but with Windows XP the usable amount of RAM is limited to 3 GB. Is this correct?

No you can go higher, with a kernel option... 3.5 at least.

I have a T60p that I have been having issues with. One of my clients has an X60 that I setup for them and used for a few days in the process - I quite liked the X60 and to date they have had no issues with it.

Due to the issues with my T60p, I am considering getting an X60 as a backup for this one.

I spend most of my time with it lid closed and external USB keyboard/mouse in it and a Dell 2405FPW attached to it - I have seen in another thread on here that the X60 can drive that monitor - so my main three questions are:
1) does the X60 have the same RAM problems that the T60 currently has?
2) how well does the X60 due with near constant usage - similar to a desktop in that it might be on for weeks at a time?
3) can the X60 use the same RAM that was in my T60p? (I have 2x1GB sticks here that I can't use in the T60p since it has a hardware issue preventing it right now)

http://www.crucial.com/store/MPartspecs ... N=CT516999



who'd have thought it would cost twice the price of the computer itself!

laughingtonto wrote:who'd have thought it would cost twice the price of the computer itself!

Ouch! I'll pass on the extra RAM, 1.5 GB is enough for me.

What about those who have to pay VAT on top of that?

Now *that* is really crazy; I have seen some memory sticks for go for $4K USD *each*. Think about that...