ECC Memory And Shuttle Athlon Motherboards?

A not-so-nameless Anonymous Coward asks: "Anyone knows of a specific instance where an AMD Athlon motherboard worked with PC100 ECC Memory? I have heard some rumors that they don't like ECC memory. I built a server, and foolish me decided to do the right thing and get the good memory: 256 Megs corsair registered, ECC PC100 strip. However, they didn't work in the Shuttle AMD K7 Athlon motherboard. Now, before you ask me why shuttle AI61, I was in a hurry and it was the only thing in hand. The 256Meg used 256Mbit chips, so I thought perhaps the BIOS didn't support 256 Mbits chips, 128 Meg PC100 ECC generic brand didn't help. Cheapo PC100 works just fine! An e-mail to shuttle went unanswered and their distributor didn't help much either."

Re:Asking sd: Why use ECC?

[Tower]

>How do you know the error correction isn't masking single manufacturing errors in the first place?

Modules should be tested in manufacturing before being shipped. This really does catch many things...

>Of all the web servers, what percentage are using ECC memory?

Well, all <I>real</I> servers use it. Not just PCs geared up to serve things, but boxes with other serveresque features (ex: IBM: RS,AS,390,Netfinity Dell: Poweredge, etc..). These are *not* stock PC backplanes (especially the RISC boxen 8^D), and ship with (usually registered) ECC memory. For everyday PCs, it's not such a big deal, since the rates are very low, and the memory isn't sustained for a long period of time. Some AS/400s, OTOH, can have areas of DRAM preserved for several years, and over time, there's far more chance for an error to occur. ECC lets you do systematic reading of the memory to 'scrub' these errors.

The rates are low, and consumer hardware doesn't need to support reporting and monitoring (extra hw/firmware, plus OS support), so 'just fix it' is usually ok...

I hope there aren't too many boards that fake it. You can ignore the ECC bits, but you shouldn't have a BIOS option to enable ECC, then...

Re:Registered, ECC - two separate issues

[Tower]

My slot-1 Abit BH-6 supports the registered ECC SDRAM that I have (256 meg sticks * 2), but I know it didn't work in another board (that supported 256 meg and ECC...)... I can't remember which that was... shoot. I'd bet that any Asus or Abit board would support it.

Re:Registered, ECC - two separate issues

[Tower]

should have made it clear that I don't have an Athlon board - the point was that registered mode is supported on some boards/chipsets, and not others...

oh, and the registered ECC tests just about as fast as my standard non-ECC sticks...

Epox K7XA w/ ECC

[LoveMuscle]

Seems to work just fine for me. Athlon 800 w/ 512MB ECC PC133.

Asking sd: Why use ECC?

[Anonymous Coward]

Yeah, duh, it corrects single bit errors, etc., but:

• Does anyone have any stats on error occurrences?
• How do you know the error correction isn't masking single manufacturing errors in the first place?
• Any mobos that will let you monitor single bit corrections for pre-emptive maintenance?
• Any that will translate real errors to paging faults, so the OS can potentially allocate another page (if read-only), load it from disk, and continue?
• Do any mobos just fake it, and not use ECC properly?
• What about ECC on L2 cache?
• Of all the web servers, what percentage are using ECC memory?

Thanks. Other comments also welcome.

ECC and Athalon - Together again

[scarl]

Athalon 500 o/c to 650 from StepThermodynamics. Asus K7M MB, 256M (2x128) Kingston PC100 ECC

There were problems when we mixed and matched 128M of PC133 non-ECC w/ the 256ECC.....it didn't seem to like it. But there have never been any problems with the ECC and the Asus board for me.

Registered, ECC - two separate issues

[justins]

The problem most likely is not the fact that it's ECC memory. The registering is more likely a problem. You probably want "unbuffered" SDRAM.

Basically, registering is a performance enhancement, ECC is a reliability feature. ECC is supported much more widely than resistering on motherboards targeted to home users.

Registered memory

[Gralbe]

I notice you said registered memory, which is a mistake I made when I built my K6-2 system. IIRC, it's the motherboard/chipset that needs to support the memory correctly, not the CPU. My new system wouldn't do anything but beep because, as far as it was concerned, there was no memory installed.

Not Shuttle's fault, see AMD Athlon FAQ

[ddstreet]

See the AMD Athlon FAQ, question [amd.com] :

Question:
My memory has all the requirements listed above, but it also has ECC (Error Correction Code). Is that a good thing?

Answer:
ECC is an excellent function for memory, but it is of no advantage for your new AMD Athlon processor-based system. In fact, it may slow down the performance of your new system. You may want to consider using memory that is not ECC.