Thinkpads Forum

Hi,

I recently upgraded my RAM from 2GB to 4GB on my T400. However only 2.5GB is available to Windows. I presume this is because I have switchable graphics. Is there anyway to reduce the amount of RAM available to the Intel integrated graphics in an attempt to open more up to Windows?

Also a supplementary question, in dual-channel mode what kind of memory bandwidth should I be seeing in Sandra? I think it's around the 5.5GB/s mark at the moment but I've seen a few people with about 50% higher than this on similar systems.

Thanks very much.

You need a 64 bit OS to use more than 3GB of ram. Do you have a 64 bit os?

No, but other people can see 3GB. So I guess my question is more related to reclaiming memory from the graphics card.

You can go into the BIOS and completely disable the switchable graphics. After a couple re-boots your computer should see 3065mb ram--At least that is what I did. Switchable graphics is crap in my opinion, a buggy setup that has caused me a bunch of crashes. It looks like they are not even offering it anymore.

reforminded wrote:You can go into the BIOS and completely disable the switchable graphics. After a couple re-boots your computer should see 3065mb ram--At least that is what I did. Switchable graphics is crap in my opinion, a buggy setup that has caused me a bunch of crashes. It looks like they are not even offering it anymore.

Thanks for letting me know about that. I haven't really had any bad experiences with switchable graphics so far, I certainly think it's the way of the future it allows the flexibility of both power saving and performance. However this is the very first implementation that's ever been used so it's bound to be a bit buggy, and it's annoying that it's not standardised enough for Linux to be able to use it yet.

reforminded wrote:Switchable graphics is crap in my opinion, a buggy setup that has caused me a bunch of crashes.

Dead1nside wrote: Thanks for letting me know about that. I haven't really had any bad experiences with switchable graphics so far, I certainly think it's the way of the future it allows the flexibility of both power saving and performance.

I think the switchable graphics is a nice feature, but the memory "loss" is just insane. I got my T500 just yesterday. Is it possible to set a limit how much memory the system will reserve to the internal intel x4500 gpu? I could not find anything in the BIOS options.

badVista wrote: I think the switchable graphics is a nice feature, but the memory "loss" is just insane. I got my T500 just yesterday. Is it possible to set a limit how much memory the system will reserve to the internal intel x4500 gpu? I could not find anything in the BIOS options.

I swear you used to be able to for the slightly older Intel Graphics chipset the X3100 but I haven't seen something in the BIOS either, sorry.

badVista wrote:
I think the switchable graphics is a nice feature, but the memory "loss" is just insane. I got my T500 just yesterday. Is it possible to set a limit how much memory the system will reserve to the internal intel x4500 gpu? I could not find anything in the BIOS options.

Only thing you can do now is disable the intel card in the bios. Then restart and reenable it if you need to switch.

reforminded wrote: Only thing you can do now is disable the intel card in the bios. Then restart and reenable it if you need to switch.

Looks like it has nothing to do with the intel card itself. If I disable the switchable graphics in the bios, the system reports
3065MB ram, regardless of which graphic card is active. Sometimes the system needs several re-boots or a power-down
to recognize the additional ram. This happened the first time after I selected the internal card, and thought the intel card
was the culprit. It seems the limitation of 32bit address space is the real reason. Both graphic cards demand its own address
range. With a 64bit os you should see 4GB ram with switchable graphics enabled. Can someone using vista64 confirm this?

badVista wrote:With a 64bit os you should see 4GB ram with switchable graphics enabled. Can someone using vista64 confirm this?

That is correct.

Cheers,

Bill B.

It is amazing to me that Lenovo isn't required to post in a huge font on its website and on the ThinkPad box this severe limitation of T400/T500/W500/W700 and probably other model machines.

People can almost contain their frustration about not being able to access 4GB on a T60 class machine. That was almost excusable since most did not need or expect to buy 4GB of RAM for their laptop.

However, in 2009 and beyond, with Vista and Win7 out, only being able to access 2.5GB with a W/T500 is ludacrous. With a fabulous new W/T500, you loose access to a half GB RAM after upgrading from a T60. It's just insanity.

At first, I thought my T500 w/4GB of RAM was defective when it displayed only 2.5GB of RAM via Win7 32-bit.

Realistically, machines offered after the T60 should be sold with 64-bit operating systems with 32-bit downgrades available after clicking through many warnings about RAM limitations.

How many people have bought computers with more than 3GB of RAM (not just Lenovo) that think they using more than 2.5 or 3GB of RAM. Probably many more than know the truth. It's a class action law suit waiting to happen. People are being sold memory they just can't (without an expensive and time consuming OS upgrade) and don't use.

underclocker wrote:It's a class action law suit waiting to happen.

If that was the case it would have happened long ago.

underclocker wrote:People can almost contain their frustration about not being able to access 4GB on a T60 class machine. That was almost excusable since most did not need or expect to buy 4GB of RAM for their laptop.

That wasn't so much Lenovo's fault. The chipset did not support it. Of course, with some less aggressive BIOS limit, one could get to 3.25GB, or even 3.5GB in some rare cases (but many machines would not be usable at that point due to insufficient PCI addressing space), but not much beyond that.

underclocker wrote:Realistically, machines offered after the T60 should be sold with 64-bit operating systems with 32-bit downgrades available after clicking through many warnings about RAM limitations.

I agree, in many ways. In fact, my opinion that Microsoft should have had the guts to never release Vista 32-bit (and definitely not Win7 32-bit). It's a new OS that's already outdated before you even begin to use it. But driver/application compatibility was a sore spot, and Microsoft did not have the guts. Maybe they were right.

However, you will find that today, after 99% of the mainstream apps/drivers are already compatible,more and more computers are being sold with 64-bit OS versions.

But I agree with you that warnings about the OS requirement to address 4GB or more RAM should be made more visible by all manufacturers.

OK let us break software compatibility.

Oh wait, 51% market saturation of 32 vs 64... There is a reason Win7-32 exists.

Or we can all just move to a BSD distro and forget all software compatibility.

For random pieces of software I've seen not work on a Vista-64 setup: Live spectrogram program, TV Tuner drivers, random accounting programs (The stuff nobody wants to care about.) and an audio editing program.

But seriously, why does WinServer 08R2 Datacenter 32bit exist?

The existence of WoW64 means that you do not in generally break software compatibility on 64bit. You do break compatibility for drivers (no choice but to rewrite them or at least recompile for 64bit), and badly written software.

When I say that MS should have ditched 32-bit, I am aware that it would require from them to work extra-hard with vendors and customers to make the transition as smooth as possible. I wish they would have done that. 64-bit would have been better than what it is, and perhaps already more software vendors would actually take advantage of that rather than just releasing their 32-bit program and using WoW.

People who absolutely cannot move to 64-bit could just stay with XP. But I guess Microsoft's decision was mostly a marketing one. They did not want those people to stay on XP - they wanted them to buy Vista/Win7.

It does make sense on many levels. But at least they could have pushed the 64-bit version harder. Look at the Linux world. Even though both 32 and 64-bit versions of all major distros exist, hardly anyone uses 32-bit anymore.