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Because if it's not, it should be!
I'm trying to get 2 x 1GB PC2700 ECC Registered DDR333 DIMMs (Micron brand) to work in my computer, but it won't POST: the computer starts, fans and hard drive spin up, but the monitors don't power up.

  • Motherboard: Supermicro X5-DAE, E7505 chipset
  • CPU: (2) Xeon 2.4 GHz
  • BIOS: 1.3b, the latest

Crucial recommends PC2700. Corsair even recommends PC3200. So I figured PC2700 would be ok. Admittedly, the manual (section 2-5) states

The X5DAE/X5DA8 supports up to 12 GB of ECC registered DDR-266/200 (PC2100/1600) memory.

but manufacturers are usually conservative.

So here's the Q: Is it supposed to work? Can I prep the BIOS beforehand, change some timings or something, or is this type of thing just a no-go in ECC land?

If you can find an example of others using PC2700 with this board let me know.

Update: I removed all cards, USB devices, cables and swapped the AGP video card out with a known good PCI just to mix things up.

Computer gives 1 beep on startup, which is normal. No other beep codes. Monitor still blank. I've tried the PC2700 pair in all 3 banks, no change. My good RAM is 2 x 512MB PC2100 ECC Crucial brand and works in all 3 banks. I tried putting the PC2100 in bank 1 and PC2700 in bank 2 hoping bank 1 would force everything to PC2100. Still nothing. Anything else I miss?

This has been resolved with the vendor as a high density memory incompatibility issue. Ebay has some literature on it:

JEDEC standard/guideline specifies that 64Mx8 and 32Mx16 devices are to be used to construct a 1GB Unbuffered module. Any 1GB Unbuffered module constructed by using 128Mx4 device BREAKS all the JEDEC standard/guideline in which is supposed to be designed only for Registered module. Since JEDEC doesn't want the modules to be built that way, so the companies who make them (a lot are generic and 3rd parties), don't put their company label on the Unbuffered modules.

share|improve this question
Item returned to vendor. In general, on eBay the most compatible RAM, low density RAM, will be brand name such as Dell, HP, etc. High density RAM is more likely to be sold generically, with no brand. So unless you know for sure that you can use high density RAM, make sure to buy RAM with some kind of brand name. – hyperslug Oct 23 '09 at 2:12
up vote 3 down vote accepted

According to Super Micro's "Test Memory List" for the motherboard, PC2700 and PC3200 is supported.

  • The tested memory for PC2700 is:
    • ATP Electronics AG64L72T8SQB3C 512MB (Qimonda chips -- Qimonda is out of business)
  • The tested memory for PC3200 is:
    • Smart Modular Technologies SM6472DDR2N1-1 512MB (Qimonda chips as well)

When you say the system won't POST, I assume POST code of 00. What POST code are you really getting? If the memory isn't supported then you should get to a POST code in the 20's (28 is a common memory failure POST code). Your motherboard is supposed to try to initialize video and display the POST code on the top line.

alt text

Something to check is to make sure the DIMM modules are fully seated.

share|improve this answer
@hanleyp, good find, that helps a lot. It might be that the RAM is bad so I can use this to demonstrate to the vendor it was DOA. I'll add more detail regarding the POST error. – hyperslug Oct 10 '09 at 5:05
You really could use a PCI POST card to see how far BIOS is getting through the boot. I've added a picture to my answer. It'll go a long way toward diagnosing the issue. – hanleyp Oct 10 '09 at 20:44
Funny, I was thinking of posting a question to see if anyone has found those things useful. Never seen one work. You use one? – hyperslug Oct 10 '09 at 20:52
Sometimes, I use them daily. Look at my "About Me" to see why. :-) – hanleyp Oct 10 '09 at 21:42
Debugging an issue like yours without a POST card is like pxxxing in the dark. – hanleyp Oct 10 '09 at 21:43

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