Question Whats the difference from Flex and Dual Channel ram

[Egehanedar]

Hi im looking for the difference from 4+4 and 4+8 gb rams,but i cant understand somethings.First i can see 4+4 is better in game performance but this is why? technically 4+8 is work at 4+4 dual and 4 single,why its worst than 4+4? i think about old laptop systems is good with 4+4 bc its good about 4+8 in game performance but i cant understand this is why,if you can explain me this detailed thank you. sorry for my bad english,im from turkey.

 

[boju]

Flex mode is partial dual channel with odd capacities. Full dual channel is better with matching capacities. Simple as that.

 

[geofelt]

Dual channel 4+4 is better for performance than just 8gb.
But, with 4+8gb, you get dual channel operation on the matched 8gb capacity and single channel operation on the odd 4gb remainder.
That is called flex mode.

To my mind, more ram is better and any difference in performance is negligible.

Then, also, flex mode implies mismatched ram which can have issues.

If you are upgrading ram, the best solution is to replace ram with a 2 x 8gb matched kit.

 

[Karadjgne]

Not just channels. You have to match up ranks when testing. Dual rank can be faster per stick individually, but slower when in dual channel as the memory controller now has 4x lanes to deal with instead of 2 that you'd get with dual channel, single rank. There's also timings to deal with, 4Gb sticks tend to have tighter timings than 8Gb sticks, so it's not hard to see performance differences between 4+4 and 4+8, if you go the wrong way. Go the other way and 4+8 could easily be better than 4+4, all depends on the actual setup.

 

[hotaru.hino]

Hi im looking for the difference from 4+4 and 4+8 gb rams,but i cant understand somethings.First i can see 4+4 is better in game performance but this is why? technically 4+8 is work at 4+4 dual and 4 single,why its worst than 4+4? i think about old laptop systems is good with 4+4 bc its good about 4+8 in game performance but i cant understand this is why,if you can explain me this detailed thank you. sorry for my bad english,im from turkey.

The reason why 4+4 in dual channel mode is faster than 4+8 in flex mode is because any time the system has to use single channel 4GB, it's cutting into the time that it could've used the dual channel 8GB. It's like if you had a two lane road, but occasionally you have to block one lane from being used for some reason.

The OS doesn't treat Flex mode as anything special, because this will complicate the way memory is managed. Flex Mode is simply to get more performance out of a less than ideal case.