RAM slots and matched pairs

**gunslinger** · 11-02-2006, 04:35

I have an intel 2.8mhz hyperthreading processor and four slots for RAM on my mobo. Currently, two of the slots contain 256mb pc2700 ddr 400 sticks for a whopping total of 512mb.

Could I put 512 mb sticks of pc2700 in the other two slots for a total of 1536mb?

What about 512 mb sticks of pc4000?

I know you're supposed to use matched pairs, but can you have two matched pairs which are different from one another?

As you can see, I'm trying not to waste the two sticks already installed. I realize I could just get a couple more 256mb sticks for a total of one gig, but then I've spent money on almost out of date stuff, and I'm out of room for further upgrades.

**Beirut** · 11-02-2006, 12:23

Perhaps you should get a strip of 1024 instead of 2x512. Not too expensive and when it's time to upgrade again, just get one more strip of 1024. That way, when you do upgrade again, you won't have a handful of mismatched RAM sitting around, just one clean GB strip to double up on.

**AussieGiant** · 11-02-2006, 13:11

unfortunately gunslinger you can only put in another set of matched 256mb. Please note you shold make them the same speed otherwise if you choose fast ram it will default back to your 400mhz speed original strips.

Beirut's idea is the best, but you have to throw out your 2x256mb sticks.

with one stick of 1gig you double your current ram...and depending on your motheboard you could possibly go up to 533mhz speed ram at the same time.

This would then allow you to add another stick later as Beirut mentions.

**Beirut** · 11-02-2006, 14:03

Originally Posted by AussieGiant

Beirut's idea is the best, but you have to throw out your 2x256mb sticks.

Maybe get a few bucks for them. Not much perhaps, but something. I got $100 for my "old" 2x512 DDR400.

**Husar** · 11-02-2006, 16:57

I know that on older mainboards I had all kinds of weird pairs installed, like EDO and SDRAM running simultaneously on one board and so on, not sure about newer mainboards. On my new board, I cannot have DDR1 and DDR2 simultaneously though it has two slots for each. Since you have only DDR1 I assume, I suggest you check the manual if you have one or have a look at the homepage of the manufacturer.

**doc_bean** · 11-02-2006, 21:52

Make sure you CAN upgrade your RAM, a (Medion) PC of ours went all crazy when my dad tried to upgrade the RAM.

**gunslinger** · 11-03-2006, 02:18

I had thought about a one gig stick, but then I read that to take advantage of the Hyperthreading on my processor/mainboard I had to use a matched pair of memory sticks.

**TosaInu** · 11-07-2006, 20:12

Gunslinger, there may be a catch.

The mobo I purchased was a quality ASUS, supporting 800 mhZ DDR. I intended to start with win98SE on it (didn't like the idea of XP), so I got only 2 sticks of 256 mb each. That would leave two slots empty and allow 1 gb when I was going to use XP. The memory was good quality with low CAS and certainly fast.

I did get XP, but the 512 was enough. Until org databases had to be edited. 512 just wasn't enough to open the big dumps. Nice: the shop still has the same sticks in stock. So I got another pair.

The PC blacked out. The deal was that everything was fine, but the mobo had problems with some DDR when more than 2 were used. The problem wasn't due to a speed, capacity or CAS mismatch, it sometimes just didn't work.

So I got 2 matched Kingston pairs of 1 gb each instead and that worked fine.

Check the website of your mobo's manufacturer and check whether there's a compatibility list. This should include brands and types.