Win 7 Ultimate RC (7600) and Maximum Memory

Factual Questions
1

Recently, my PC went tits-up so I decided to splurge and build myself something decent.

I’ve got an Intel i7 processor with 12GB of memory on it. Well, actually, it’s got 10GB because I had one bad stick, but still. 10GB, we’ll say.

My BIOS sees 10GB.

Win 7 Ultimate (Build 7600) shows 8GB.

I checked the “maximum memory” setting in msconfig, and it’s not checked. I’ve tried looking around the internets, but I can’t find any references to RC versions being limited to 8GB (and it would he a terrible idea if they did).

Anyone have any idea what could be going on?

-Joe

2

Memory limits for Windows operating systems can be found here:

Windows 7 Ultimate 32-bit supports up to 4GB RAM and Windows 7 Ultimate 64-bit supports up to 192GB RAM.

One possibility is that you are running Windows 7 Ultimate 32-bit. That OS is only capable of addressing 4GB of RAM (really, 3.X GB of RAM). However, Windows 7 will report the amount of installed RAM in the system, even though it cannot actually address the entire memory space. This is in contrast to Windows XP 32-bit that will only report the amount of addressable RAM. Not sure why it would be reporting 8GB instead of the full 10GB if this were the case, though.

If you’re running Windows 7 Ultimate 64-bit, then I’m stumped.

3

Not sure how you ended up with 10gb, what memory cards do you have and how are you 2gb short?

Sounds to me like something is funny from the getgo.

Otara

4

The Core i7 uses triple-channel memory, so presumably he’s got 6 2gb sticks, one of which is bad.

5

Does the system use pairs of memory? Maybe your system still runs with that unmatched stick, and the board is just disabling it.

6

Ding! You win today’s mindreading prize! It is triple channel, there are 6 2GB sticks, and one of them is bad.

Anyways, yes, it is a Win 7 Ultimate, 64-bit install. As I said, BIOS is seeing 10GB, so it can’t be a matched-pair kind of scenario.

So, still looking for ideas.

-Joe

7

Replace your bad memory stick is going to be an excellent place to start

8

Sure, but that will take me from 10GB to 12GB…which still is more than 8GB.

Blargh.

-Joe

9

I have a vague remembrance of a post on another forum which said being limited to 8 GB was a hardware limitation of certain chipsets in combo with Windows 7. But I cannot remember further details. I do remember reading a thread on Sudhian / SFFTech that there was a problem with Shuttle H7 boxes suffering extreme slow-downs with more than 8 GB and that was fixed with a BIOS update.

Also, have you ensured that it is the last socket that is empty?

10

Yes, at one point I did NOT have the last socket empty, because I’d pulled the bad chip and not rearranged things. Now it’s the last socket that’s empty.

And a bit of trivia for those interested - if you buy your RAM in a 3-pack from OCZ you’re going to have to return the RAM as a 3-pack to OCZ.

-Joe

11

Could it be that it sees 10gb but only uses 8gb because of the matching issue?

As in if you turn off interleaving or the like, it might be seen then.

Otara

12

I haven’t worked with triple channel yet, but could it be because one of the sets is missing a stick that it runs as dual channel, and makes your other set run as dual leaving one stick out?

In other words can the system run one channel as triple channel, and the other channel as dual channel?

System sees all 10GB, but can not use the last 2GB stick so Windows does not report it.

-Otanx

13

Well, I’m working on the RMA process now (in which I have to send back all 3 sticks from the same batch, since they ship in triplets), so I’ll let everyone know what happens when I’m fully stocked back to 12GB.

On the positive side, I’m “only” running 6GB, and the thing runs like a dream.

-Joe