[kadoban]

When built my last machine, I looked pretty hard for ECC RAM. What I could find was _very_ slow and something like twice the price.

Do you have any suggestions at all for where to look?

Also, is it really just lack of XMP and having to OC manually? My impression was that you could expect extremely little OC to be stable even if you did it yourself.

[thulle]

> My impression was that you could expect extremely little OC to be stable even if you did it yourself.

Not my experience at all. I bought a Ryzen 3700X with 4x 16GB 2666MT/s Kingston ECC. Memory chips turned out to be Micron revision E, same as used in many popular Gaming XMP sticks.

I could run these at 3333MT/s and lower CL from 19 to 14. Thus, raw latency going from 19*2000/2666=14.2ns to 8.4ns. After recently buying a used Ryzen 5950X I can now push the memory to 3600CL14, or 7.77ns. At this point I'm at the limit of what I can cool without starting to hear my PC.

> What I could find was _very_ slow and something like twice the price.

And at this point I'm running my memory at the same speed as G.Skill Ripjaws V Black, which is the fastest gaming memory I could find available here, but the G.Skill is twice the cost. Though, I see that it's also available as 4600CL19, and I actually never tried decoupling the memory clock from the fabric clock after upgrading my CPU since I couldn't push 4 sticks fast enough on my 3700x that I'd make up for the decoupling. I should probably try it out. Suspect I won't hit 4600MT/s though, but I don't think I would be able to run the G.Skill att 4600CL19 with 4 sticks either.

[theevilsharpie]

> Do you have any suggestions at all for where to look?

I've bought from Memory4Less in the past and had a good experience. ServerSupply was also a source I used for work, although I don't think I've ever bought anything from them for personal use.

> Also, is it really just lack of XMP and having to OC manually?

Yes.

> My impression was that you could expect extremely little OC to be stable even if you did it yourself.

All other things being equal, I would expect ECC RAM to have somewhat lower overclocking headroom than non-ECC memory, because the memory controller has to drive an additional memory chip with a wider memory bus. However, I generally wouldn't expect significantly worse results than the manual overclocking that enthusiasts did in the past. Obviously, as with any overclocking, your mileage may vary.