01-25-2014 10:23 AM - edited 01-25-2014 10:33 AM
(Cross-posted from the Desktops forum on an Expert's recommendation)
I have an HP Z800 workstation with 16Gb ram, and I want to up that to 48Gb.
This helpful document on the HP site - HP Z800 Memory Configuration and Optimization - states:
* The HP Z800 supports Unbuffered 1GB single rank and 2GB dual rank PC3-10600E 1333MHZ ECC DIMMs
* The HP Z800 supports Registered 4GB and 8GB dual rank PC3-10600R and PC3-10600P 1333MHz DIMMs
But the data sheet
for the currently installed RAM - (four times 4Gb sticks, Samsung Part # m393B5270dh0-yh9) , says this is 4Gb single-rank -
What I understand from some reading is that single-rank might have some small latency advantage due to the lack of the ranking buffer. And apparently the Z800 can support it since that's what's in there - it doesn't have to be dual rank as the HP doc says. (Or maybe saying it supportds dual rank implies it can also support single-rank?)
So - I'm shopping for additional 4Gb sticks - I know I should not mix single and dual rank.
I can find dual-rank sticks cheaper than single rank. Tossing the existing sticks and buying 12 new dual-rank would actually be cheaper than adding 8 new single-rank. But is there a performance advantage of the single-rank?
Do I ditch the existing and get all new double-rank 'cause it's cheaper and performs just as well, or do I shop for new single-rank and pay the premium 'cause it performs so much better?
01-27-2014 06:10 AM - edited 01-27-2014 06:11 AM
In the meantime - I've found the exact same sticks as already in the achine - Samsung Part # m393B5270dh0-yh9 - at a good price - better than the dual-rank. So now I'm hoping the single-rank is actually better - or at least close to equivalent - in terms of performance. If it matters, the Z800 is being used for music and video editing, and I'll be going 48Gb in 12 x 4Gb.
Same part #, same Samsung sticker on the stick - just not an HP branding sticker - but I'm guessing they all just stick their stickers to the same stick from Samsung.