i815 SDRAM Question

[senior guy]

I've been told that the i815 chipset can not support more than 512MB of PC133 CAS2 SDRAM. Is this true regardless of which i815 motherboard is used?

Can someone please give me the facts on i815 memory limitations and restrictions.

Thanks!

 

[Sloth]

It is true. The 815 and 815E are limited to 512. The new 815EP is 2GB (I think) but so far it is just starting to show up.

Another limit of the chipset is addressing the ram even within the 512 limit. If you have a board w/ 4 slots you can only use 3 of them if your ram is double sided. If I remember right it would be slots 1,2 and 4 to do it.


S.

 

[AndyHui]

All i815E/P chipsets are limited to a maximum of 512MB.

The chipset supports 6 RAS lines, or 6 sides of memory. That translates into a maximum of 3 double sided DIMMs. If you have a board with 4 DIMM slots, then the last two DIMMs must be single sided.

You can run all 3 DIMM slots at 100MHz, or only 2 DIMM slots at 133MHz. Somehow ASUS managed to get around this limitation on the CUSL2 series of boards and can get all 3 DIMM slots running at 133MHz.

 

[senior guy]

Ok, so are you saying that if I get an 815EP mobo with 4-DIMM slots, it will fully support 4 x 256MB of PC133 CAS2 SDRAM?

 

[senior guy]

Woops, I didn't see Andy's post before. Now I'm really confused!

 

[AndyHui]

i815EP does NOT support 2GB of SDRAM. It only supports 512MB.

 

[senior guy]

Andy~ in your prior post, you said "Somehow ASUS managed to get around this limitation on the CUSL2 series of boards and can get all 3 DIMM slots running at 133MHz". Doesn't this mean that the CUSL2 will fully support 3 x 256MB (768MB) of PC133 CAS2 SDRAM?

 

[Spoooon]

I think that all he meant is that you can get up to 512 megs of RAM at 133 even if they occupy all three slots. The 512 limit still applies... Asus just got around the "You can run all 3 DIMM slots at 100MHz, or only 2 DIMM slots at 133MHz" thing.

 

[przero]

ABIT claims that the 815 will not support 256meg chips. How about it?

 

[subhuman]

Running 2 sticks of crucial at 2,2,2, 144FSB, Asus CUSL2 (i815E). Both 256meg chips.

 

[Vegito]

I'm running 2 stick of 256mb = 512 crucial and also have 1 stick of 512mb crucial pc133.

No problem here.

Asus board supports 3 slot at full pc133 speed providing max is 512mb ram. Board will not recognize more than 512mb ram. So you would have 2 128mb = 256 + 1 256mb = 512 total

 

[oldfart]

I have two 128 meg and one 256 meg Crucial on a CUSL2. All 3 slots used and runs peffect @ 133 FSB cas 2-2-2.

 

[przero]

This is copied off fo ABIT FAQ for SA6R board:

The Intel 815 chipset (and also 815E) does not support 4x4, 8x4, 16x4 or any other x4 memory chips. A wide variety of errors is possible if you try to use double-sided 32MB chip modules or single-sided 16MB chip modules with this chipset, including system crashes or failures to POST.

So, I contacted Intel, They said support for different chips was a motherboard manufacturers decision. Now they all, including ABIT claim to support 256 meg chips until you buy the boards. Now...What's up with that??

 

[senior guy]

Thanks to everyone who responded. From what I've learned here, the 815's 512MB limit is too much of a constraint for me to base my new build on.

While typically, 512MB is much more than anyone needs, Photoshop (generating large printouts) is one big memory hog!

 

[Z24]

What's the (PIII) alternative to i815 based boards if you want more than 512 megs?

 

[AndyHui]

BX, i820 (yeah right...), Apollo Pro 133A, Apollo Pro 266 are alternatives.

The BX supports 1GB of SDRAM, nobody knows what the i820 supports and the VIA chipsets support 1.5GB of RAM.