Raptor Computing Systems Community Forums (BETA)

Raptor Computing Systems Hardware => Blackbird => Topic started by: surf on May 21, 2020, 04:15:19 pm

Title: Blackbird memory options...
Post by: surf on May 21, 2020, 04:15:19 pm

So the manual for the Blackbird doesn't have much to say about the memory, besides:

DDR4 1600/1866/2133/2400/2666 ECC

The wiki says more:

must be registered (RDIMM); must NOT be LRDIMM.
The supported memory speeds are 1600, 1866, 2133, 2400, 2666 MHz.
Ram will be running at a potentially slower frequency (2666, 2400, or 2133) based on if there is 1, 2 or 4 DIMMs per channel

So as a noob to this stuff, what is a good approach to picking RAM for the Blackbird?  For example, would 2 8GB sticks be better than a single 16GB?  Or is it better to leave a slot open for a future upgrade?  How much does the speed matter?

Title: Re: Blackbird memory options...
Post by: MPC7500 on May 21, 2020, 05:06:33 pm

I wouldn't look at speed, since most of them run at 2666MHz anyway.
I would buy as much RAM as I want to pay for it. I would buy 32GB (€130).

The performance is of course better if both slots are in use.

Title: Re: Blackbird memory options...
Post by: ClassicHasClass on May 22, 2020, 09:45:10 pm

The other question is rank. I haven't gotten a straight answer on this from the IBM docs.