RAM compatibility

Forums › Desktop computing › RAM compatibility

aucklander

478 posts

Ultimate Geek
+1 received by user: 11

#27492 28-Oct-2008 12:07

Hi!

I have installed right now 2x1GB RAM, matched pair DDR2 800. Mobo supports higher speeds, but with the processor I have 800Mhz is the highest. I am planning to add 2x512 DDR2 667 as a matched pair.

What is the speed after this addition? Is it going to be 667 for all 4 memories, or the mobo is able to run two of them at 800 and the other two at 667?

assuming the final speed is going to be 667 for all memories, is this going to impact on the performance at a level where I can actually feel it? The pc runs as dedicated HTPC, no games. The video card is enough for HD tv decoding but definitely NOT suitable for decent games, anyway.

mobo Intel DH55PJ, RAM: 4GB RAM, Nova-T 500 HD + Avermedia Trinity tuner card, Geforce 520 video, 120GB SSD Sandisk + 640 WD + 1000SG, Win7 Home Prem 64-bit, Media Portal 1.15.0; BTC 9019URF Cordless Keyboard, Panasonic 55" (HDMI cable), HTPC Case Silverstone Grandia GD05B.

Overclocker01

176 posts

Master Geek

#174610 30-Oct-2008 13:07

Why not just add another ddr2 800 1gb ram. it may cost you a couple of buks more but your pc is going to run better having all your ram operating at the same level i.e 800...

xpd

Geek of Coastguard
14115 posts

Uber Geek
+1 received by user: 4574

Retired Mod

ID Verified

Trusted

Lifetime subscriber

#174628 30-Oct-2008 14:48

I know back in the old days (SDRAM), the RAM would drop to whatever the slowest RAM speed was....
ie: 1 stick of PC133 and 1 stick of PC100, the PC133 would be dropped back to PC100.

If thats still true I dont know... Id assume it would be.

XPD / Gavin

LinkTree

aucklander

478 posts

Ultimate Geek
+1 received by user: 11

#174661 30-Oct-2008 16:35

I found that pair relatively cheap on TradeMe and it was a "matched pair". But I agree, it would be safer to get DDR2 800. I have 4 slots on the mobo, divided in two channels. Do I have to fill the second channel (both slots) or would be ok to use first channel (2x slots) and only one slot of the second channel?

I found a reference somewhere about the bandwith alocated to RAM if both slots in a channel are used... only one slot used, and the performance is not the same, apparently. That's way I was planning to get a second "matched pair".

I think I will get 1x1GB DDR2 800 mem stick and see how it goes...

askelon

942 posts

Ultimate Geek
+1 received by user: 233

ID Verified

#174700 30-Oct-2008 18:16

If you add the 512's the ram speed will drop to 667.. Some motherboards are a little funny and require you to stick the slowest ram in the first bank to set the speed though.