VNF4/Ultra Zenith VE and 4 1GB Dimms Confusion

[rls2002]

I'm a little confused.

I bought this MOBO to support my digital photography habit. I read an article by Tim Gray of Microsoft that suggested using 4 GB of memory to optimize digit throughput with Photoshop CS and other graphics programs.

I have 4 1 GB dimms of GEIL Unbuffered PC3200 memory that I want to use on this motherboard. I also have an Athlon 64 3200+ (Venice) processor. I have flashed the bios to the latest version (06/03/2005). When this setup boots the memory is clocked at 333 mhz rather than 400 mhz and counted as 347872KB. Windows XP Pro sp2 only knows about 3.25 GB of memory.

What is the reason that the DDR400 timing and 4 GB total memory are not recognized and used?

I am not an overclocker and I know very little about which bios settings if any that need to be changed to attain optimal performance.

Is there anything I can do to get all of the memory recognized? What about getting the DDR400 speed?

I am looking for stable performance while enjoying all the benefits that this motherboard has to offer.

Any suggestions? Have I mistakenly invested in a motherboard that can't provide the performance I was looking for?

 

[boomerang]

I can't give you a definitive answer but I'll try to help.

Download and run memtest on each module individually. It's quite possible you have some bad sticks.

This could also be a double sided/single sided issue. Unfortunately, the Chaintech site does not provide a wealth of information. They do have a document concerning memory they have tested with this board, and call out specific single sided and double sided sticks that worked. However, just because your memory does not appear on the list does not mean that it will not work.

They have a FAQ section, but do not have any info on 939 boards.

See what results you get with memtest.

This is a pretty popular motherboard. My reply will bump it up and maybe someone will see it with a true answer for you.

 

[StormRider]

There was a detailed thread in Ars Technica about the 4 GB limitation

Using all 4 GBytes

Apparently, the reason can be a combination of the OS, cpu, motherboard, bios and chipset. It looks like that area is reserved for memory mapped i/o and stuff and that's why you're only seeing about 3.25 GBytes.

I don't know why your memory speed dropped down to 333 Mhz. With all 4 dimms sockets filled, the memory controller sometimes drops the speed down to maximize stability but I thought the Venice chips were supposed to be able to drive it at 400 Mhz with all 4 sockets filled.

 

[Concillian]

1) 32 bits of address space = 4GB. Many I/Os are mapped with addresses that get taken up and can't be used for RAM addresses. I believe a 64 bit OS will solve the problem with this.

2) The A64 memory controller will not support 4 double sided DIMMs at the same performance that it will support 2 double sided DIMMs, there should be a note about this in your motherboard manual. ( I downloaded your manual from Chaintech and it only alluded to the limitation at the top of page 8, didn't really spell it out)

With a Venice core you can TRY manually setting BIOS settigs under frequency voltage controle to 200 MHz RAM speed and 2T command rate (some will call this CPC OFF), but I don't think it's guaranteed success.