Using ECC memory on an ASUS P3V4X? (VIA Apollo Pro133 chipset)

[goingware]

I need to increase the memory in my machine, which uses a P3V4X motherboard. The 128 MB DIMM that's there fails test with memtest86 so I'm going to remove it. (Note that it doesn't noticably cause trouble during normal use, and it passes the POST - it's only after lengthy stress-testing that the old memory fails test).

This is a workstation used for software development, so I don't want there to be any bugs in the system I didn't put there myself!

I'd like to use ECC memory for it. I can find only sparse information about it's ECC support. Asus'
specification page says that it offers "ECC or parity support" but I can't find any mention of it in the manual. Micron also says it supports ECC.

I had thought that all the systems that supported ECC would allow you to enable or disable it in the BIOS, but I can't find any mention of this in the manual or by exploring the BIOS config options. The one exception is that there is an option to enable ECC in the processor level 2 cache, but that's a different thing.

What I'm wondering is, can I select whether ECC is enabled, and does the fact that it supports ECC mean only that it will work if ECC memory is installed, or that error correction will actually take place if I have it?

Here's Crucial's selection of compatible memory for the P3V4X. As I post this, PC133 with ECC and CAS 2 is $57.59, while without ECC it's $52.19 for 256 MB, so I think it's well worth the few extra dollars.

While some are skeptical of the frequency that cosmic rays will cause trouble, I'm pretty convinced that very small defects in manufacturing can cause more frequent errors. Memtest86 shows this consistently.

 

[bluezebra1098]

ECC Memory will function if the memory is stand alone on the board. If you mix Non ECC with ECC the memory will default to NON ECC just as if you mix PC 100 with PC133 the faster memory will default to PC100.
Also remember that running more than two double sided memory chips with the VIA chipset could cause problems.
Good luck

 

[Peter]

The VIA chipsets that don't have integrated graphics do support ECC memory (and actually do ECC ) - and normally, with up to six rows (three DIMMs), stable operation is achievable. Four unbuffered DIMMs is difficult, with any chipset.

However, you're always better of with fewer large DIMMs than with many small ones. VIA 693A north bridge can handle 256-MBit technology (today's "VIA-only high density" SDRAM) in the first two DIMM slots and 128-MBit in the latter ones - if the mainboard design uses that feature. Else, you're limited to 256 MBytes per DIMM (using 128-MBit technology SDRAM chips).

regards, Peter