2 RAM options : 1 Gb PC2-5300 or 1.2 Gb PC2-4200 ?

[pierre04]

Hi,

I just bought a X60 (with one stick of 1 GB PC2-5300 5-5-5-12)

A friend gave me a spare 256 Mb stick of PC2-4200 4-4-4-11

I have to decide what is better for me : Keep my actual config, or plug the 256 Mb and have my whole system run at lower ram speed, but with more RAM. (will it work as dual channel ?)

I mainly use this laptop for websurfing (firefox), word processing, spreadsheets (OOo) et sometimes do some photo editing ~10 Mpx each file (gimp). I use Debian Linux (stable)

I will soon do a few memtest session to have some numbers, but I already know they do not reflect every-day use.
I might try to measure some kernel compilation time also

Do you think of any other test to have real world numbers ?

[RealBlackStuff]

AFAIK you machine could run with 2x 2GB PC5300, although under Windows 32-bit it only recognizes 3-3.2 GB.
The extra 256MB doesn't bring much, certainly not if it brings the bus-speed down.
Dual Channel only works when 2 equal RAM modules are in it.

[pierre04]

I know I could buy some RAM for 30 € or so, but 1Gb is enough for me.

Here are some memtest results.

1 GB

Bandwidth = 1985 MB/s
Clock speed : 609 Mhz (DDR 1219) @ 5-5-5-15
FSB : 304 Mhz - Single chanel 64bits

1DB + 256 MB

Bandwidth = 1881 MB/s
Clock speed : 508 Mhz (DDR 1016) @ 4-4-4-12
FSB : 304 Mhz - Dual chanel asymetric

I plan to compile a kernel before this week-end.

[pierre04]

After some linux kernel compilations I can say the time is exactly the same !

I also ran some benchmark, such as Fibonacci, MD5, SHA1, Blowfish or raytracing and the difference is less than 1%

Looks like there is no big difference, so I will probably keep 1.2 gb to avoid some swapping to occur.

Any other benchmark ideas ?