Is there a performance hit for mixed DIMMS?

[profBIll]

2Gb in my SR MBP is proving to be a little less that I need, especially for parallels. I was thinking of buying just a single 2Gb stick, replace one of the 1Gb sticks, to get a total of 3Gb.

My question was whether there is a performance hit to have mixed DIMMs in the system? Anybody seen a performance loss with 3Gb of memory? Any help appreciated.

>>>bill<<<

 

[mad jew]

It almost certainly won't be a performance hit if you're finding 2GB isn't enough RAM. The benefits of having enough RAM versus having slightly faster matched chips are much greater.

 

[CanadaRAM]

Your hit for giving up dual-channel will be about 6%
Your gain on having more RAM will depend on how you use the machine --

if you are regularly exceeding 2 Gb RAM now and paging out to the hard drive, then you might see as much as 20% gain.

If you operate now entirely within 2 Gb and close programs religiously when not in use, and your don't see any PageOuts, then you may not see any gain from the extra 1 Gb.

 

[docc]

I'm using 2.5GB RAM on my macbook and the performance is MUCH higher in comparison to stock 1GB RAM it came with.

 

[vicious7]

I also started getting pageouts with all the software I was running concurrently so I went up to 4Gigs. And I'm now much happier. OWC has some good deals on matched sticks.

 

[CD3660]

I got this upgrade from OWC: Works perfectly!

http://eshop.macsales.com/item/Other World Computing/53IM2DDR4GBK/

 

[vicious7]

I got this upgrade from OWC: Works perfectly!

http://eshop.macsales.com/item/Other World Computing/53IM2DDR4GBK/

Yep, that's the one...

 

[profBIll]

That is exactly what I wanted to know. Thanks very much to everyone who chimed in.

>>>bill<<<

Your hit for giving up dual-channel will be about 6%
Your gain on having more RAM will depend on how you use the machine --

if you are regularly exceeding 2 Gb RAM now and paging out to the hard drive, then you might see as much as 20% gain.

If you operate now entirely within 2 Gb and close programs religiously when not in use, and your don't see any PageOuts, then you may not see any gain from the extra 1 Gb.