[SOLVED] Speed - SSD vs M.2 vs M.2 Ultra?

[hobkirk]

I've read that a hard drive is much slower than a SSD, which itself is much slower than M.2, and that M.2 Ultra is significantly faster yet. But none of the articles quantified the differences. So I started digging and ended up at Wikipedia "IOPS" (Input/output operations per second). They often show several examples for a specific type of device - I roughly averaged them.

1. HDD = 0.170K (15K drive, small blocks - i.e., the best case for a HD)
2. SSD, SATA 3 = 8 K (speed increase over HD by 40x)
3. SSD SATA 6 = 80 K (further speed increase by 10x)
4. NVMe over PCIe 3.0 x 4 = 380 K (further speed increase by 5x)
5. Flash/DRAM = 1 M (further speed increase by 2.5x)

Why would anyone build a performance PC and not use NVMe over PCIe 3.0 x 4?

• The 3 M2.0 Ultra chosen by Tom's Hardware only cost $55, $120, and $170 (250 GB - 1 TB)
• Motherboards with Ultra M2.0 at New Egg start at $75 (15 under $120)

Questions:

1. Do I have this mostly right?
2. Can I use the M2.0 Ultra on a MB for an old CPU (i5 6500)? NewEgg lists 4 boards under $125 (3 out of stock):

Thanks...

 

[richiestang_78]

M.2 is nothing but a form factor and has nothing to do with speeds. They have SATA and PCIe speed M.2 drives and its depends on the motherboard what one it uses.

M.2 PCIe NVME drives will not work in a SATA only M.2 slots, however some slots support both SATA and PCIe speeds so you need to check the motherboards specificications.


Now getting to the actual real world speeds. SSDs are faster then HDDs in most cases except many "bargain" SSDs are DRAM less meaning they have no on board cache and in many cases will be as slow if not slower then a HDD because of it.


Then you have the types of files being read and write, gaming for instance is typically random read meaning that SSDs will be faster then most HDDs for game but between SATA SSDs and PCIe NVME drives the actually difference can be negligible. A couple years ago most people would say save the money and just get SATA SSDs however given that the cost difference between them is so small now most people will recommend a NVME over a SATA speed unless your computer doesn't support it or you are on a very tight budget.

 

[USAFRet]

Why would anyone build a performance PC and not use NVMe over PCIe 3.0 x 4?

$$
A 1TB Samsung 970 EVO (NVMe) is significantly more expensive than a 1TB Samsung 860 EVO (SATA III)