Windows doesn't boot with 16 GB of RAM
 

So I wanted to expand my RAM. My computer has four slots and I was running with 2x4GB, and before that with 4x1GB which was the OEM's configuration. I had tried mixing 2x4GB+2x1GB but it caused freezes (incompatible RAM timings maybe?). I bought another pair of 4GB sticks, as identical to the two I had as absolutely possible without being made the same day, and from the same manufacturer.

When it's time for Windows to start, the computer just freezes. I have Vista x64 Home Premium, whose top is 16 GB precisely. And besides from what I've read if you surpass these limits Windows works just the same, but with capped RAM.

It doesn't seem to be due to my Windows installation, as the same happens with the bootable installation DVD.

With 12 GB for example Windows works OK, although Windows reports 11.9 GB (12,221 MB), but this may be unrelated. It doesn't seem to be caused by a defective stick or slot. I have swapped the sticks in place and actually it works the same if I fill DIMM slots 1-3 or 1-2 and 4. It always worked fine with the OEM configuration, which was 1 GB sticks filling all four slots.

I have run both the OEM-provided memory diagnostics and MemTest86+ with negative results. MemTest86+ for one reports 4x4096MB correctly.

The BIOS reports 16 GB in dual channel. With three sticks, which is the most I can run Windows on, it reports 12 GB in "flex mode", so everything looks fine. Although then on the detailed list the BIOS also reports any 4 GB stick as 512 MB, but that may be unrelated too. I have the latests BIOS update (from Dell, from 2009). At any rate the problem appears when Windows is supposed to enter the stage.

I have tried booting an Ubuntu CD, and it runs OK, but this time reporting 14.7 GiB...

I recall in XP this sort of thing was related to the fact that the RAM, pagefile and the GPU all shared a common address space. How much memory does your GPU have and what is your page file set to?

My graphic card has 1 GB, and currently after expanding to 3x4GB, my pagefile is 13,129,252,864 bytes (12.23 GB) big. I read the MSDN article about memory limits, but I found nothing that would explain this. AFAIK with x64 there should be no problem.

http://msdn.microsoft.com/en-us/libr...(v=vs.85).aspx

I don't recall any version of XP being 64 bits friendly or even compatible though.

I clearly remember that 4gig of ram being an almost impassable mark in XP power output. Not that I don't think it would be possible to go around or above it, but more for the fact that Microsoft is well known for blocking their products to promote the newer ones for milking cash.

There was a Windows XP Professional x64 Edition, which supported up to 128 GB, but before this becomes derailed, I'll repeat that I have Vista Home Premium x64. I have been working with 8 GB for a long time.

I would say, almost certainly, a motherboard limitation. Just because I can fit a 4 GB stick in my netbook, I know the memory controller won't accept over 2 GB. I would look up the specs for the motherboard.

You may well be right, although unfortunately Dell doesn't provide proper documentation at this level. I think it's a (possibly customized) Intel motherboard, but I'm not sure which one. According to Memtest86+ and HWiNFO it may be "x48", which apparently has 8 GB max. At Intel.com it wasn't recognized as Intel.

But at any rate it does seem to accept 4 GB sticks. With 8 GB I think I've worked long enough to be sure that there are no problems. Nevertheless this might explain my issues while using 10 GB (2x4+2x1), as well as the diminished tallies (11.9 GB instead of 12 and 14.7 instead of 16). I'll be on the alert in case any problem comes back with 12 GB, then I'll know what to expect.

Thanks.

Maybe you could use the CrucialSystemScanner. Link
I have used it every time I needed to increase the memory available for the system to it's max..

The only things I get of this site is then:
Type of RAM (DDR2, 3 and/or SODIMM etc.)
Maximum (In GB over all slots)
Speed (noted as PC(#-)#### and/or a (#)###MHz value)
CAS latency (CL#)
and Voltage (between 1,5V and 1,9V I think)

After I know what I need through this utility, I simply use those values to shop for the best RAM where I think it's sold Cheapest. ^_^

8 GB is definitely the max for my mobo. I can sail uncharted waters with more RAM in some circumstances, but it causes freezes in the long run. Serves me right. :|

Ah well, if you can't add more mem to speed things up you always can get one of those: SATA2 DDR2 HyperDrive5
It's unbelievable how fast things work with them drives.
Could testrun one not so long ago ( ...had to give it back, damn ) and yeah, anything that uses a lot of mem/HD-read-writings/HDcache , CAD, video-converting, such things, run fast as hell.

Now yeah, speed has a price, of course.

here is your answer Japo:

I could write an epic rant about Dell but it wouldn't be useful in any way. So I shorten it to: Dell is crap and I'd never use it as my hardware@home ever.

Sorry can't help you on this one.

16 gig!? Are you insane? Even Bill Gates said that 640k ought to be enough for everybody!

I'm kinda astonished that nobody mentionend a bios update before. (neither me :lol:)

had some trouble to get my 1866 RAM working on full speed but after the bios update I found an extra profile with the correct RAM-timings and since then it works like a charme...

edit: ok, just read you stated to already have the latest bios. in this case looking a bit around in that bios can't hurt. I found that profile in the bios of mine under d.o.c.p. (dram overclock profiles). auto-detect and memOK! didn't work and always set it back to just 1333...

At this date, any RAM over 8GB even with a Windows 7 x64 OS is wasted unless you have an application (not a game) that is specifically programmed to use that much RAM. Otherwise, most games, even the newest beasts such as Skyrim, will only use 4 GB and then switch over to the Page File.

Are you running multiple VM's or something Japo!? :) In a server instance running VM's is the only time I'd see the need for that much RAM.

Yes but not quite, it's 2 GB usually and 4 GB if specifically programmed. But that's 32-bit applications, x64 applications get 8,192 GB:

http://msdn.microsoft.com/en-us/library/aa366778.aspx

Of course that much memory is useful only to share among several applications. You can always set up a virtual disk though. :D At any rate I don't have to worry about the performance bottleneck, no matter how many applications I'm running at the same time. And yes I can run VMs like there's no tomorrow. :P But really I'm just a nerd, and RAM is really cheap, I just wanted to max the computer out before the price of DDR3 started to go up with time after it's superseded and become rarer.

Well it's maxed out now. :P I realize I have 8 GB and just now retail "pro" computers are beginning to pack 6 GB. :max: The whole point about this computer, that's almost four years old, was that I wouldn't go bankrupt buying it, but also because I don't plan to replace it for a looong time yet.

Well a bit late, but maybe the ram is not compatible with your motherboard. Though if it's DELL, might be hard to find out what kind of board you have. Other idea is that the sticks you bought are paired up. Meaning that the first two have to be in 1-2, the second in 3-4, depending on how the RAM slots are Ganged. Third idea is going into BIOS, and adjusting the RAM timer manually.

No, by now the problem has been perfectly identified. There has been no problem since I cut back to 8 GB. I was just dumb enough to plan an upgrade without looking at the motherboard manual--and lucky enough that, even though it was designed for 2 GB sticks at most, 4 of them at most, it works with 4 GB sticks too (as long as you don't plug more than 2, of course).

As I said the motherboard is a Dell version of a particular Intel one, but I have no way of knowing whether it's been modified only to print Dell's name, or further. But the memory's been working without trouble for a long time now, and it was always well paired (sticks bought together)--not that it's necessary, the computer can also work in single or mixed channel without trouble. Of course I didn't buy it from Dell, they expect you to pay triple, but by now it's clear it works with my motherboard. Though now I understand why Dell's website offered no sticks bigger than 2 GB for my computer...

Also Dell's BIOS doesn't allow you to tweak anything, no overclocking, no manual memory timings, nothing. It's possible that the motherboard is so identical to Intel's non OEM version that Intel's BIOS worked, but I'm not going to find out. Specially since all works great now.