[SOLVED] Why is my SATA SSD performing better than my PCie SSD?

[Myronazz]

Hello...

So I got my new M.2 PCIe SSD today, it's a Corsair MP510. I installed it, then cloned my Windows installation from my SATA Samsung Evo 840 SSD. So after that, I naturally grew curious of how better it performs since its my first M.2 drive and downloaded CrystalDiskMark to test it out.... and my SATA 840 evo blows the MP510 out of the water? What? Unless either the software is somehow broken, or I am an idiot and don't understand storage benchmarks because admitedly I don't really bother with this sort of thing often.

Here is my NVMe SSD, which is now my main drive:

And my old, 840 Evo connected to a SATA3 port (which actually died two times but revived itself as many times somehow):

I turned on RAPID mode for the 840 evo but surely that cannot make THAT big of a difference. So what in the world is going on over here? I thought PCIe drives are several times faster. not several times slower. How does the Evo even perform like this? I thought that SATA was limited to around 750 MB/s and yet the readings here are far beyond that... so how in the world is this a thing?

 

[TJ Hooker]

I turned on RAPID mode for the 840 evo but surely that cannot make THAT big of a difference.

It makes a huge difference. If you're testing with RAPID enabled it's as much a RAM benchmark as it is a SSD benchmark. For instance it is impossible to get over ~600 MB/s on a SATA III interface, which gives you an idea of how much RAPID is inflating your scores.

 

[Myronazz]

It makes a huge difference. If you're testing with RAPID enabled it's as much a RAM benchmark as it is a SSD benchmark.

Oh alright, I see now, I did research on RAPID mode and it all totally makes sense now... I'll turn it off since I don't have a need for it, and I don't really have that much RAM on my system so I'd rather not go wasting it like this. Really cool feature though!