4x1GB Modules?

Just got 4x1 Gig sticks of DDR400 ECC memory for my new dual opteron system.

Windozes reserves about 1/2 Gig of memory of things like PCI rom bios, etc.
So you will only have around 3.5 Gig of useable memory.
Plus no aplication in windows can use more than 2 Gig of memory I think.

The other drawback is heat./ power draw.
It takes a lot of power to run 4x1 Gig of memory.
So if your PSU, MOBO, Cooling are not top class then your not going to be stable at high speeds.

Plus to get high speeds you realy need to buy all 4 sticks at the same time to make sure you get as close to identical sticks as possible.
So mega $$$.

Luck......... :D
 
Lol, 4 x TWIN2X1024-5300C4PRO

The Corsair DDR2 stuff.


LOL, just kidding. That stuff is way too expensive.
 
Tigerbiten said:
Windozes reserves about 1/2 Gig of memory of things like PCI rom bios, etc.
So you will only have around 3.5 Gig of useable memory.
Plus no aplication in windows can use more than 2 Gig of memory I think.
Luck......... :D
Click to expand...

It is not windoze that uses the 1/2 gig but the particular motherboard itself.

Most motherboard will let you have all 4 GB.
There just been a few motherboards that need to use 1/2 GB.
 
spectrumbx said:
It is not windoze that uses the 1/2 gig but the particular motherboard itself.

Most motherboard will let you have all 4 GB.
There just been a few motherboards that need to use 1/2 GB.
Click to expand...

Yep, BIOS dictates the size of the memory hole below 4GB, but there must always be a memory hole. In most cases, memory is reallocated above the 4GB address (ffff:ffffh) so that the OS can see the rest of the memory. I'm not sure which flavors of MS OSes can use > 4GB, but I know that for some, you need to enable PAE in the OS (2k?)

Addressing below 4 GB is necessary for the physical ROM part (resides at 4GB-ROM Size), AGP aperture (normally 64M or larger), any PCI card with memory (like a RAID controller w/ cache), etc.. Everything needs to have an address in the system. You can't have both memory and something else in the same space, so the memory just gets either ignored, or re-addressed above 4GB. Bear in mind that with PAE, you can address 36-bits in most processors (disregarding chipset limitations), so the real upper memory limit is 64GB, although it's messy to access that way...

Option ROMs tend to use the 640K-1024K range, not the high ranges.

In BIOSes I have worked on, sometimes we would determine the minimum memory hole necessary based on the resources needed by the hardware. Sometimes we would just say 1/2GB ought to do it...
 
"So you will only have around 3.5 Gig of useable memory."

That's funny :)
 
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