Question SATAII faster than SATAIII?

Mar 1, 2019
Hi guys,

Just grabbed a new SSD (Patriot Burst 480GB) and installed it, but right away noticed a strange thing - its speeds in SATAII port are better or around the same as in SATAIII.
My MoBo has Marvel controllers for the 6Gbps ports so I figured that would be the case, but are they really so bad that it's better to use 3Gbps ports?

Tested with CrystalDiskMark6:

Seq 32T1 read 262.8 vs 243.4
Seq 32T1 write 273.7 vs 186.0

4KiB Q8T8 read 205.2 vs 28.53
4KiB Q8T8 write 209.0 vs 50.86

4KiB Q32T1 read 156.6 vs 24.49
4KiB Q32T1 write 145.6 vs 51.53

4KiB Q1T1 read 26.57 vs 18.94
4KiB Q1T1 write 45.80 vs 31.53

SATAIII is literally worse in every scenario.
The early Marvell SATA 3 controllers had a bad reputation for corrupting data. I wouldn't at all be surprised if they weren't capable of full SATA 3 speeds either.

This review of the Patriot Burst 480GB shows fairly normal SATA3 speeds. So i don't think it's the drive.

That said, your 4k QD1 speeds are fairly close to the review. Unless you're editing movies or making multiple copies of large files, that's the really important figure. It's the slowest operation of a SSD, so what usually bottlenecks its performance. Not the sequential speeds that everyone incorrectly drools over. So I'd just live with it on a SATA 2 port. If it really bugs you, you can buy a SATA expansion card with a better SATA 3 controller. Just be forewarned that not all of those support booting off a connected drive.
The review I read showed CrystalDiskMark speeds of ~500 MB/sec sequential reads (seq Q32T1), so it should run near typical SATA3 spec speeds....

240 MB/sec for Q32T1 seq reads is about half speed, for whatever reason...(perhaps having some older SSDs that are SATA2 spec caps the controller to that speed for all ports? Might need to test as the sole OS drive connected to get peak speeds?)


Many motherboards with the
marvell sata3 controller were crippled by only being on a pciex1 link back the the northbridge. This was further crippled by the two ports getting only half the bandwidth even when only 1 drive was installed.

I'm willing to bet you have one of these motherboards, I do too. But the good news is even on Sata2 you get 90% of the benefit of an SSD. it only operates at max speeds during Sequential transfers and most home users hit the random 4k aspect. I have another identically spec'd pc except for a different motherbd and the Sata2 system actually boots faster then the sata3. Go Figure! LoL