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I have 2 GB of PC3200 DDR-DIM memory in my PC, 2x1GB, and I just found a 1 GB memory chip which has the same latency 2,5 settings but it is from TwinMOS and the 2 GB I have installed is from Kingston.

The Kingston chips are running in dual channel mode, 128 bit. If I install the third chip which my mobo supports it won't be running dual channel anymore, but how much would that affect the memory speed overall? Does anyone have a good freeware program I can test before and after I install the chip to see if it has a negative affect on my machine? Would be sweet to have 3 GB of RAM

Try downloading Sisoft Sandra and running the memory latency and bandwidth tests.

Trying that now

I always use it to test new hardware, like to compare my gear against all the others.

Man, that was dissapointing.

2 GB old setup:

Memory bandwidth:
3854 MB/s
3883 MB/s

Latency test:
105 ms
Speedfactor: 67,1

Max mem bus bandwidth
6432 MB/s

402 MHz data rate.



3 GB test setup:

Memory bandwidth:
1987 MB/s
1981 MB/s

Latency test:
117 ms
Speedfactor: 77,6

Max mem bus bandwidth
2672 MB/s

334 MHz data rate.


Very big difference there. Think I'm gonna stick with my "old" setup.

Oh, btw Vista rating gave me a dissapointing surprise aswell:

Before with 2 GB I got 4.8 rating, 4.9 on memory.

After with 3 GB I just got 4.1 overall and 4.1 on memory.

Interesting I have an Intel iMac at the moment it does have 1 gig of RAM in one slot, so it can't use it's duble channel mode, for christmas I'm going to buy another gig of RAM for the second slot, seems like this will really push my performance a bit. Can't test with Siseof Sandra though since installing windows is an absolut no go for me, I put it either in a VM where it is a slave to the other OS^^or on one of these grey boxes^^ Iw want to install Linux on my Mac though. But I'm still a little frightened for that^^

Remember that if you want to run the memory in dual channel mode the memory chips have to be identical, meaning coming from the same batch number. If I remember correctly.

Wow, thats a big drop. bet you're glad you tested it now.

Yeah, the reason I wanted to test it was because a friend of mine a few month ago bougth some more RAM for his PC and when I took a benchmark his memory was more then half the speed after the new memory was installed. Kinda what happened here. More RAM doesn't mean more speed, keep that in mind

I see the latency didn't change that much. But yeah you lost over half the bandwidth there. Why the MHz drop? Was the 3rd one a slower one?
Dual Channel require paired memory.
And the slowest/worst memory in a system dictate the overall performance of the memory. (lowest common denominator)

Although I have not tested, I believe 4 sticks of 512MB gives better performance than say 4 sticks of 1GB. (larger sticks has larger latency)
DDR2 has higher latency than DDR as well, but higher MHz obviously.

Just stay away from no-name brands, buy something midrange in paired kits.
The performance should be pretty good for any use, unless your a pro game freak or similar.

Like my DDR2 ram, I tried to manually tweak the settings to maximize memory handling to the chips. After lots of rebooting and almost destroying my bios due to some reflashing... I ended up with the conclusion that the AM2 Athlon 64 did a better job automatically adjusting the memory settings. (memory controller inside the cpu) so my bios memory setting is now at auto... which was the default setting even. *sigh*

PS! With AM2 Athlon (which uses DDR2 memory) the faster the cpu, the better the memory will perform.

Yeah, the 1 GB RAM chip I tried was only 333 MHz. So both the other got turned down to 333 too.

So wha do I have to do, to get a memory Chip which will be capapoble of doing Dual Channel with my other Memory chip installed in my iMac, do you think because ale iMacs obviously have the same memory chips the guys at the local contract Apple store will be able to give me a matching chip?

PS: maybe my last post seemed like I am hatig Windows, thats not really true though, it just doesn't fit on a Mac I think, somehow tradition forbids it, would be like a BMW engine in a Mercedes^^neither of them are bad but they just don't fit together^^

Not sure really, what I did was to buy a 2 GB matching kit. Both RAM chips came in the same package so I would be absolutely sure that they matched and would run in dual channel mode. But I guess you can check the part number of your chip and search on online stores if they have a matching one. I'm not 100% certain it would work.