Author Topic: Mixing different RAM Speeds? (Read 725 times)

Wilbus · « **on:** December 15, 2007, 06:07:15 AM »

I am currently using 2x1gb 533mhz memories, DDR2. I was thinking of buying two more x 2gb memories to get 6 total (mainboard supports 8gb) but was thinking about getting 800mhz PC 6400 instead. Will it work? Will I fry something or will the PC 6400's work on the same (lower) speed as the ones I currently have installed?

Thanks in advance.

Ghosth · « **Reply #1 on:** December 15, 2007, 06:28:09 AM »

Why?

Windows XP won't see over 3 gig. And if your running vista, well, ehm, DON'T!

Ghosth · « **Reply #2 on:** December 15, 2007, 06:29:56 AM »

ps, if your going to put them ALL in there, better to stick with the same speed.

If your going to buy 4 gig of the new faster why slow it down by putting the slower ram in?

But then you always were a "RAMaholic" Grin

Fulmar · « **Reply #3 on:** December 15, 2007, 07:35:58 AM »

Actually the price of the faster ram is maybe a dollar or two more (or cheaper!) than the 533mhz stuff. So why not get the faster stuff? It under clocks itself and lets say you upgrade your motherboard in the future (thinking that you stay with DDR2, so it'd have to be an upgrade within a year-year and a half) you could keep the faster ram that would work better with a CPU with a faster FSB.

It won't fry anything either.

I actually have 4gb of ram. Windows detects 3gb, and the bios shows 3.5gb. AH sees 2gb and so do some other programs. I bought my RAM for future upgrades to possibly 64 bit windows depending on my needs (not there yet). So unless you're going to go 64 bit windows, 4gb is the absolute max.

OOZ662 · « **Reply #4 on:** December 17, 2007, 12:50:30 AM »

Motherboards will automatically run ALL RAM at the LOWEST speed installed. The 800mhz sticks would be downclocked to 533.

If you're going to buy two 800mhz and your motherboard supports that speed...just chuck the other two. You'll see a pretty good performance increase (if your RAM is actually your bottleneck) with just that.

MrRiplEy[H] · « **Reply #5 on:** December 17, 2007, 09:12:16 AM »

Yeah it's not a problem if you lose 1 gig of ram due to 32-bit xp. Your XP will be maxed out on ram and should the need arise in ~2 years to move to 64-bits your hardware will be outdated by then anyway.

hyster · « **Reply #6 on:** December 17, 2007, 11:27:48 AM »

XP can see 3.5 gig of ram.
i have 4 gig installed. i did this nowing that XP cannot see 4gig but putting the 4gig in means that all my modules can run under duel channel memory mode.

http://www.devhardware.com/c/a/Memory/Dual-Channel/

Quote

Originally posted by OOZ662 Motherboards will automatically run ALL RAM at the LOWEST speed installed. The 800mhz sticks would be downclocked to 533.

100% agree

OOZ662 · « **Reply #7 on:** December 17, 2007, 11:29:35 PM »

32 bit operating systems handle 4 gigabytes of OVERALL systemwide RAM. That includes RAM, RAM on the video card, RAM on the sound card, ect.

Have a 512mb video card? Then you can only have a little under 3.5GB of system RAM.

Fulmar · « **Reply #8 on:** December 18, 2007, 12:02:25 AM »

Quote

Originally posted by OOZ662
32 bit operating systems handle 4 gigabytes of OVERALL systemwide RAM. That includes RAM, RAM on the video card, RAM on the sound card, ect.

Have a 512mb video card? Then you can only have a little under 3.5GB of system RAM.

But mine shows I have 3.5gb and I have 640mb on video memory!

OOZ662 · « **Reply #9 on:** December 18, 2007, 12:04:30 AM »

Is it rounded?

Balsy · « **Reply #10 on:** December 18, 2007, 09:00:40 AM »

Quote

Originally posted by OOZ662
Is it rounded?

If it is.. he pushed it in too hard.

Charge · « **Reply #11 on:** December 19, 2007, 07:58:57 AM »

Since the memory prices are low (except DDR3s) I'd put two identical 1Gb memories preferably with as fast internal clocks as possible and dump the old RAMs. Ensure that your mobo supports the faster RAMs.

-C+

Wilbus · « **Reply #12 on:** December 20, 2007, 12:23:46 AM »

Oh wow, thanks for the replies. Sorry for the late response, I was woundering why noone replied as I didn't get any mails about it, guess I need to check my settings and see if something has changed.

I actually had no idea XP couldn't see more then 3-4 gb RAM, that's kind of sucky, but good from a price perspective...

As for moving to Vista... I won't be doing that in a long time, probarly not as long as I've got a free will.

So how about just exchanging the PC5400 memories I have for 6400 800mhz memories? Will I see much increase in performance there?

Not sure if I have a real bottleneck really but using the graphic programs I am for picture editing more/faster RAM is never bad.

How much difference is there between quality memories and cheaper ones?

Thanks again and sorry for late reply.

Wilbus · « **Reply #13 on:** December 20, 2007, 12:25:15 AM »

And yes of course I've always been a RAMoholic, that's the only way I get kills

OOZ662 · « **Reply #14 on:** December 20, 2007, 01:56:59 AM »

Check the manual for the fastest speed of RAM you can have. I believe it's the same as the FSB speed.

RAM timings are listed in strings (I believe of four), like 2-1-1-2 (I made that up). It's called the latency. The higher the numbers, the slower and lower quality the RAM. Look into premounted heatsinks for extended life if you plan on using your computer for a long while.