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Differences in ram kits

Racer2k5x

35 months ago

So I'm in the market for a new computer and am looking at parts. I'm wanting 16gb of ram for gaming and slight editing. Should I go with a 2x8 kit or 4k4 kit what's the difference in performance?

Comments

  • 35 months ago
  • 1 point

If you're using a Skylake or Kabylake (LGA 1151) or AMD Ryzen (AM4) CPU, there is no difference beyond not having any memory slots free for an upgrade, so a 2 x 8 kit is optimal. If you're using an LGA 2011-3 CPU then when installed in the right slots a 4 x 4 kit would mean higher memory bandwidth, assuming other specs are the same. In that case whether there's ultimately a performance difference depends on what you're doing with your PC.

  • 35 months ago
  • 1 point

How would ,on a kabylake i5, a 4x4 kit differ from 2x8 other than esthetics or future upgrades?

  • 35 months ago
  • 1 point

If the kits are otherwise identical in specs, then there won't be much difference. The only place I could see there being a difference is 2-way rank interleaving if the 8GB DIMMs in the 2 x 8 GB kit are single rank. In that case the 4 x 4 kit would mean higher bandwidth with mixed (read/write) workloads for this subsystem and in some situations will provide lower access latencies by allowing for different ranks to be accessed concurrently. So in some specific scenarios the 4 x 4 kit can have a performance advantage depending on which 2 x 8 kit you're looking at (assuming otherwise pretty similar specs), but it's not like it will be a massive difference.

Such small details are only ones you should worry about if you want to maximize your PC's badassery, you're using your PC for something that is time consuming and memory performance sensitive, and/or performance directly affects profits, the latter of which is highly doubtful if you're even on here in the first place.

I know that you're going with a Kaby i5, but for anyone reading this and isn't already aware, remember that the AMD Ryzen memory controller is more sensitive to the higher electrical load from more ranks, thus more ranks will mean running lower DIMM speeds. So Ryzen requires more consideration when it comes to memory performance.

  • 35 months ago
  • 1 point

I'm staying away from ryzen untill more of the launch bugs get fixed with it.

[comment deleted]
  • 35 months ago
  • 1 point

whether there's ultimately a performance difference depends on what you're doing with your PC.

For programs "responding quicker" you're going to want to look at your storage instead. Memory access latency is in the span of nanoseconds, even if we assume a high queuing latency at the memory controller where it's still measured in nanoseconds. It's going to take milliseconds for you to see and even process the input to begin with (something exploited with GPUs), so memory bandwidth and anything within reason that will affect main memory access latency won't really affect perceived latency in that way.

[comment deleted]
  • 35 months ago
  • 1 point

Well, programs load some of their data into the RAM to allow that code to be run without reading/writing the disk every time something needs to be done...

And doing that requires reading from the storage drive(s), in which case memory bandwidth and access latency is going to be a pretty small contributor in the time it takes to do that. Also see my just-edited comment before this one.

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