4GB in Vista 64bit - s939

[Job]

thought might have some more responses here - see original thread http://forums.anandtech.com/me...id=34&threadid=2082818 if im missing anything from this post.

4 gigs of Ram installed, all the same brand/timings/etc - PC4000 - basic problem is, System is not nearly stable without a MASSIVE reduction in Memory bandwith, and pitiful OCing on the CPU.

After 2 days of testing with a new opty 185 - the only way I can stay stable is running the proc at 2.7 and the ram at 165 mhz! This is unacceptable, so I have gone back to 2 gigs of ram running at 240mhz and the proc running at 3 ghz - tbh, the system is faster and more responsive without the extra 2 gigs of Ram.

Vista optimum at 4 gigs my arse. Plus - no crashes! God bless Microsoft. Now all I need to do is to find a way to cool my chipset below 58 degrees, seeing as there's a giant 8800gtx sitting on top of the fan...... haven't tried xp 64 yet, but would love to know if it works any better.

Don't get me wrong, my system is very snappy. In fact, it is slightly faster running less ram at a higher frequency. I just don't like the idea of 2 gigs of Ram sitting on my desk going unused!!

Any one think this 4gb issue will be cleared up with a service pack (assuming its not a motherboard issue)? Many s939 users seems to be having similar problems - how does it work for you guys with newer chipsets?

 

[MaxGeek]

I've heard of some weird issues with Vista X64 and 4GB of ram. Some people who originally had 2Gb and upgraded to 4GB reported some issues. However I doubt that Vista is the cause of your problems. It's more likely the memory controller on the Opteron. A64's never really liked 4 sticks of ram that much. Most people have to run 2T. Have you tried testing memtest (dos) and orthos memory test in windows? If you can't pass memtest its not windows fault.


I personally had issues with 4x1GB of ram. Originally it all worked, but one stick died and when I got my RMA it was the same ram but a different batch #. I couldn't get it stable at the same 1100mhz again and had to run at ~900mhz. I ended up ordering another set to get the same batch.

 

[Job]

I was prime 95 stable for 5 1/2 hours with 4 x 1GB but running games proved a bit iffy sometimes, not to mention the huge decrease in memory speed - this was runing 4GB PC4000 3-5-5-10 2T @ 216 mhz - I was perfectly stable at 162 mhz, but that really is just taking the p@%#!! I shouldnt have to run my ram 88mhz slower than its rated speed just because there's four sticks in there.... does your ram need to run slower/looser timings?

I'm beginning to think s939 just wasn't designed to run 4GB without massive losses in speed.....

 

[Mr Fox]

Originally posted by: Job
I was prime 95 stable for 5 1/2 hours with 4 x 1GB but running games proved a bit iffy sometimes, not to mention the huge decrease in memory speed - this was runing 4GB PC4000 3-5-5-10 2T @ 216 mhz - I was perfectly stable at 162 mhz, but that really is just taking the p@%#!! I shouldnt have to run my ram 88mhz slower than its rated speed just because there's four sticks in there.... does your ram need to run slower/looser timings?

I'm beginning to think s939 just wasn't designed to run 4GB without massive losses in speed.....

NVIDIA Chipsets are extremely sensitive to this kind of Configuration especially with AMD having the Memory Controller on the CPU.

939 and 940 were dual channel but only meant to populate 2 slots

 

[aka1nas]

You are running 2T command rate when you have 4 sticks installed, right?

Running 4 sticks WILL increase the stress on the memory bus and you will likely have to back off your OC on a chip with an IMC.

 

[n7]

A64 on nV chipset + 4 dimms = issues for heavy OCing, guaranteed.

The on-die memory controller is a great thing, but it kills OCing with four dimms.

Even with Intel, 4 dimms = a lot more hassle OCing than 2 dimms i find.

Nothing to do with OS in this case.

 

[Job]

Thats definitely something i've considered - but then I hear similar problems from ppl with 2x2gb sticks -

 

[lopri]

Originally posted by: n7
A64 on nV chipset + 4 dimms = issues for heavy OCing, guaranteed.

The on-die memory controller is a great thing, but it kills OCing with four dimms.

Even with Intel, 4 dimms = a lot more hassle OCing than 2 dimms i find.

Nothing to do with OS in this case.

I used to feel the opposite. Most of the time, I knew I was doing something wrong when there were stability problem on A64 platform. A64's on-die memory controller's quality is so much higher than various intel chipsets' memory controllers, IMO. When going with 4 DIMMs, most of the time all I had to do was to set command rate from 1T->2T.

As a matter of fact, there are quite a few desktop boards that support up to 16GB of RAM (well, at least on the spec sheets) on AMD side. On Intel side, I haven't seen any desktop board supporting more than 8GB of RAM.

 

[aka1nas]

Originally posted by: Job
Thats definitely something i've considered - but then I hear similar problems from ppl with 2x2gb sticks -

Hehe, you can't really win either way, as higher density sticks do seem to stress the memory controller more, though IME not nearly as much as adding more sticks. That's why the OCers making all the world records are running piddly amounts of RAM like 2x256 or 2x512. Usually, you only might lose 100Mhz or so of your max stable OC adding another pair of sticks. You really won't notice the difference in CPU speed, but you will notice the performance difference if you are short on RAM.

 

[Job]

definitely - 4gb running at 324 mhz with a 2.9ghz CPU feels slower than 2.6ghz CPU with 475mhz on the ram. Although, I could just stick with 2 gb and go up to 3.1ghz on the cpu with 520 mhz on the ram.... decisions decisions........

 

[Yellowbeard]

I certainly will not say anything bad about any particular MOBO maker. However, I have done some OCing on 939 with 4 DIMMs on a different board from what you have. If you have the option, you may want to see if a differnt 939 board may handle the OCing load better.

 

[Cerb]

For X amount of RAM, you need at least X*Y of your stuff on the chip, and it's going to take X*Y in square area. All else being equal, a larger chip will have more units that run slower, and/or don't work fully. Oh, and you've got many of these chips on your stick of RAM, and it only takes one to cause you problems. Your mobo's voltage regulation, BIOS, and chipset can make a good bit of difference, but only so much.

2x2GB can help when it comes to a stable bus and keeping the voltage up in transients, but won't fix the above problem. If you can get a board that will support at default settings, and OC well, 4 sticks, great. But even then, you may have to choose between more RAM or faster RAM. While it may not show in benchies, more is always the better way to go when faced with that choice.