X8 DDR5 vs X16 DDR5 Memory

[KING19]

The results are pretty shocking.

 

[Sandy Bridge]

What's the summary for those of us conserving out bandwidth by preferring text/images to video?

 

My guess is it's that in some use cases DDR4 is as good as DDR5.  MSI did a study on this: https://www.msi.com/blog/a-closer-look-at-ddr5-benchmarks-with-intels-Alder-lake-cpus  The tl;dr is that at the same capacities, top-of-the-line DDR4 can match or exceed most DDR5.  Two relevant charts:

 

 

 

So that 3600 C15 vs 4800 C40 is pretty close for write speeds at the same capacity, and 4800 C20 DDR4 wins over 4800 C40 DDR5.  Presumably DDR4 3200/3600 is cheaper than DDR5, although whether 4800 C20 DDR4 is going to save you any money over DDR5, I'm not so sure...

 

What I don't know the answer to yet is why doubling the capacity helps so much with DDR5.  It should be dual-channel in all cases in the second chart.  But it seems to be relevant.

 

Now if the video is looking at game benchmarks... I wouldn't be surprised if the difference is negligible.  Unless they're running on integrated graphics, faster RAM usually doesn't have major impacts on game frame rates.  And DDR5's weakness at this early stage of its lifetime is its latency - the DDR3 in my desktop (9-9-9-24 1600) will beat any of the DDR5 that MSI was able to test in latency, and DDR4 almost always wins too.  So for a game that is more dependent on latency than bandwidth, DDR5 might do worse.  Latency should improve as DDR5 matures... but it's the tradeoff of jumping on board early, along with the higher price.

 

IIRC, workloads like compression and encoding are more likely to benefit from DDR5's bandwidth improvements.

[KING19]

DDR5 is still new so its going to take more time for it to mature, Even looking at the benchmarks its still not worth the price for it right now imo especially with real world testing. The only good thing about DDR5 is that it caused DDR4 RAM prices to drop!.