Different size memory sticks...

kesava8@hotmail.

kesava8@hotmail.

banned
I currently have a 512 mb pc-4200 533mhz stick of ram... i have just bought a 1 gb stick ( same specs)

my question is, will there be a problem as they are different sizes?

also, (my system is in my signature) will i notice a decently large difference in performance?

thanks
 
Bandwidth doubles in dual channel mode. In single mode 64 bit is transfered at a time, in dual mode it's 128 bit.

Benchmarks generelly shows, that in real world applications the performance gain/loss is small.

Some memory controlleres are smart enough to run dual channel over some of the ram, and single on the last. Yours is somewhere between that. It can do it, but software must be written specially to use it (because of the way memory addresses are spread out between the DIMMs)
 
StrangleHold said:
If he runs one 1gb and one 512 it will not run in dual channel, he wont be between anything, it will just run in single channel!
Click to expand...

There are two modes in his chipset: asymmetric and symmetric

when the amount in both channels are not equal (or only one channel is populated), the memory controller runs in asymmetric mode

chipset 945P: http://www.intel.com/design/chipsets/datashts/307502.htm

Newer memory controllers have the "flex" mode, which ping-pong the addresses between the DIMMs, so normal applications can benefit from it also

http://support.intel.com/support/motherboards/desktop/sb/CS-011965.htm#flex
 
When running one 512 and 1gb stick your only going to get 64 bit bandwith regardless of mode. Your not going to get 128 bit bandwith so your still running in single channel with a fancy name
 
Have you read my links?

Dual-Channel Asymmetric

This mode is entered when both memory channels are routed and populated with different amounts (MB) of total memory.

With the aid of Intel Flex Memory Technology this configuration allows addresses to be bounced between channels in interleaved mode until the top of the smaller channel’s memory is reached, allowing for full dual channel performance in that range. Access to higher addresses will all be to the channel with the larger amount of memory populated; thus giving single channel performance through those addresses.

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The older memory controllers did it differently, they didn't bounc the addresses between the channels
 
yes but didnt you say that flex mode is avaible in newer chipsets? therefore i cant use it? anyway will i still see a big difference in performance?

i think i might buy another 1 gb stick. then it shall perform much better right?

because then i will have 2 gig running in dual channel rather than 1.5 gig running in single channel.

is this right?
 
yes but didnt you say that flex mode is avaible in newer chipsets? therefore i cant use it? anyway will i still see a big difference in performance?
Click to expand...
Flex mode is on the 945 and later chipsets so you can use it. I would still prefer to match RAM size if you are trying to use dual channel but whatever you stick in should be running at least partially in dual channel.
 
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