Several months back I put together a test box with 4GB of what I thought was relatively “premium” memory. As it turns out, I was mistaken.

The latest Ubuntu 6 install CD offers a menu choice to run Memtest86+ v1.65. This box is going to be my long-term (hopefully) home file server. Since I had not run a memory test before, seemed like a good idea to run one now. At this point the box had been running for 8 months without any noticable errors.

First thing I noticed was that the motherboard BIOS had auto-detected the memory as DDR300 with 2.5-3-2-5 timings. This considerably slower than DDR400 with 2-3-2-5 as spec’d by the manufacturer. So I used the manual settings in the BIOS to match what I thought I’d bought - and about an hour or so later got errors(!!). Dropped the timings from 2-3-2-5 back to 2.5-3-2-5 and dropped the memory clock rate back one notch. Again, got errors about between 1-2 hours into the first pass. After dropping the clock rate a couple more times, finally at DDR333 ran for 12 hours (over 7 complete passes) without a single error.

  • Looks like the DDR400 memory I bought is really DDR333.
  • Looks like the BIOS autodetect guessed right!
  • Not running a thorough memory test earlier was a mistake.

From the errors I saw, I suspect that only one of the four sticks is under-spec, and the other three might indeed perform at DDR400. By now there is no point in figuring out which (and waste hours more).

So … if for no other reason, get a Ubuntu 6 install CD for the bootable memory test! It also comes with a pretty nifty operating system.

Update: Got an email from a OCZ support guy. He suggested bumping DRAM voltage by +0.2V. Tested - no change. BTW - Memtest86+ is slightly inaccurate when reporting the DDR rate (i.e. DDR333 is reported as DDR315).

Update: Got the following e-mail from OCZ back in July, then nothing.

From: “Sean K. Sinha” <sean@ocztechnology.com> To: “‘Preston L. Bannister’” Subject: RE: Under-spec memory? Date: Wed, 12 Jul 2006 10:23:45 -0700

Preston,

Let’s evaluate and replace your memory for you under warranty, as it should be able to run at DDR400 with the voltage increase. You are not trying to run at a 1T Command Rate/CPC Enabled with four modules inserted, correct?

We are sorry about the problems you have experienced. Please provide us the following information for RMA.

Then we will send you an email with RMA# and instructions for shipping. Please allow up to 24 hours for a response. If you have any other questions, please feel free to let us know.

We would be happy to take care of it for you.

After a couple months (and a couple reminders sent by me) nothing more has come from OCZ. Seems the “Lifetime Warranty” they offer does not mean anything.

Was reminded of this when shopping for a 4GB SD memory card for my camera. No, I will not be buying an OCZ product.