4x4GB vs 2x8GB

[FurryTij]

What's the difference between the two in performance? G.Skill Ripjaws 16GB (4x4GB) and G.Skill Ripjaws 16GB (2x8GB). Apart from that you get 4 thingos with the 4x4 and 2 with the 2x8, is there any difference? Like, performance-wise?

 

[rene13cross]

There is a slight performance difference. Using dual or quad channel memory controllers will make use of as many DIMMs as possible but in this case there would be no felt performance increase, perhaps for some benchmarks... Getting 2 8GB DIMMs is a bit more future proof in that you will have space to upgrade easily in the future if you ever feel the need to.

 

[chimera201]

^this
u also need to have a mobo and cpu that supports quad channel memory architecture to have a performance boost over the 2x8GB config. The cpu will be more of a bottleneck for the 4x4 config

 

[weaselman]

Its all to do with Bandwidth, As the guys are saying Four sticks in quad channel will result in a memory bandwidth of this.
EG: 1 stick of memory = 64 bits of data transferred at at time. Quad will be 64+64+64+64
= 256 bits of data at a time.

 

[swifty_morgan]

depends on the processor. the old 920's ( 1156 I think they were ? ) ........ ( not the tri channel processors )......... had funky memory controllers. running 2 sticks was faster than running 4 because of the way the memory was read.

I don't know why but..........i just put together ( half put together ) a zeon quad core and used 2-4gig and then 4-4gig and the 4-4gig is slower. i haven't had time to look into this ( waiting to get rest of parts ) so I don't know why this is happening.

I would get 2 sticks which is what I'm going to do around xmas time to give it a try.

 

[jaquith]

The CPU determines the number of channels, not the number of sticks of RAM. Both the CPU and RAM's Frequency & CAS Timings are the determiners of performance.

That said, in synthetics you might see some differences based primarily on the RAM's IC's and the fact of two sticks per channel, but if the 4x4GB & 2x8GB have the same rated Frequency and CAS Timings the real world differences will be at most <1%.

The only reason to get 16GB or in particular 2x8GB is if you plan to do some form of 'Rendering.' For Gaming I'd recommend 2x4GB or 8GB of RAM assuming a 64-bit OS. My sole issue with 8GB/stick RAM on 'consumer' CPU's (non-ECC) kits is their error rates, and as the RAM's IC's become better so will the error rate become less. All RAM throws ~1-2 errors per month.

 

[weaselman]

You mean the density of the ram becomes the problem the smaller it gets in NM because of electrical Migration of the circuit path ways ? ECC is slower anyway due to the extra parity check. But as you say if the case of Data integrity a good choice.

 

[jaquith]

I see more issues with 8GB/stick density in non-ECC type RAM, it is what it is and as the IC's become more matured then I'd suspect the problems to be reduced. Generally, 8GB/stick CAS Timings are one notch slower than their 4GB/stick density counterparts.