Question effects of DRAM on SSD Random Read speed

[visibleman]

I am shopping for a new M2 SSD and am trying to balance features/performance against price (like 99% of folks, I guess).
The computer in question has 2 gen3 M2 sockets and I want to replace the current Sata SSD with a new, bigger M2.

Currently it has a 1 TB Kingston A2000: https://uk.pcpartpicker.com/product...-m2-2280-nvme-solid-state-drive-sa2000m81000g
CrystalMark (v8.0.6) benches this at roughly:

• 2200 MB/s sequential read
• 58 MB/s random read (4kQ1T1)

I have also bought a 1TB KIOXIA EXCERIA PLUS G3 (to replace the sata SSD) and I am trying to determine if I will keep it or look for something else to get more performance.
Yes, it is a gen 4 ssd in an gen 3 slot. I reasoned that while it wouldn't give gen4 speeds, it would get close to max gen3 performance and at £47.99 why would I buy gen3?
CrystalMark (v8.0.6) benches the Kioxia at roughly:

• 3400 MB/s sequential read
• 62 MB/s random read (4kQ1T1)

The sequential read is close to gen3 max (which is what I hoped), but the random read is a marginal increase over the gen3 Kingston.

There are lots of benchmarks and reviews, but they all focus on the sequential Write & Read speeds (which is great when installing a AAA game), but I have read in several places that the Random Read speed is probably a more useful metric when playing games.
It doesn't help that specs for random read speeds are reported in IOPS (if at all) while benchmarks seem to be in MB/s

This Samsung 980 Pro review has crystaldisk (version unknown) benchmarks for several gen4 drives with DRAM cache:
https://www.guru3d.com/review/samsung-980-pro-1tb-nvme-ssd-review/page-14/
Only two of the drives show any significant increase for Random Read speed over my current gen3 and gen4 DRAM-less drives.

So, onto the actual questions...

1. Based on these benchmarks, it feels that DRAM has little to no benefit for random read speeds - is that correct?
2. If it is true that random read doesn't benefit from DRAM, what is causing that significantly higher read speed on the Samsung ssd?
3. Are there any other gen4 drives with read speeds similar to the Samsung?
4. Would the increase from ~60MB/s to 88MB/s actually be noticeable?

 

[CountMike]

I am shopping for a new M2 SSD and am trying to balance features/performance against price (like 99% of folks, I guess).
The computer in question has 2 gen3 M2 sockets and I want to replace the current Sata SSD with a new, bigger M2.

Currently it has a 1 TB Kingston A2000: https://uk.pcpartpicker.com/product...-m2-2280-nvme-solid-state-drive-sa2000m81000g
CrystalMark (v8.0.6) benches this at roughly:

• 2200 MB/s sequential read
• 58 MB/s random read (4kQ1T1)

I have also bought a 1TB KIOXIA EXCERIA PLUS G3 (to replace the sata SSD) and I am trying to determine if I will keep it or look for something else to get more performance.
Yes, it is a gen 4 ssd in an gen 3 slot. I reasoned that while it wouldn't give gen4 speeds, it would get close to max gen3 performance and at £47.99 why would I buy gen3?
CrystalMark (v8.0.6) benches the Kioxia at roughly:

• 3400 MB/s sequential read
• 62 MB/s random read (4kQ1T1)

The sequential read is close to gen3 max (which is what I hoped), but the random read is a marginal increase over the gen3 Kingston.

There are lots of benchmarks and reviews, but they all focus on the sequential Write & Read speeds (which is great when installing a AAA game), but I have read in several places that the Random Read speed is probably a more useful metric when playing games.
It doesn't help that specs for random read speeds are reported in IOPS (if at all) while benchmarks seem to be in MB/s

This Samsung 980 Pro review has crystaldisk (version unknown) benchmarks for several gen4 drives with DRAM cache:
https://www.guru3d.com/review/samsung-980-pro-1tb-nvme-ssd-review/page-14/
Only two of the drives show any significant increase for Random Read speed over my current gen3 and gen4 DRAM-less drives.

So, onto the actual questions...

1. Based on these benchmarks, it feels that DRAM has little to no benefit for random read speeds - is that correct?
2. If it is true that random read doesn't benefit from DRAM, what is causing that significantly higher read speed on the Samsung ssd?
3. Are there any other gen4 drives with read speeds similar to the Samsung?
4. Would the increase from ~60MB/s to 88MB/s actually be noticeable?

1. all data goes thru RAM cache but affects writing speed more until filled. It also depends on it's configuration, simple FIFO (First in, first out) or predictive(more efficient), all controlled by drive's firmware.
2. Some drives use DRAM cache for writing only.
3. Yes Kingston KC3000 for instance.
3. No.