SSD performing better in SATA 2 than SATA 3

[Imriela]

I have a Samsung 850 EVO SSD and when I got it, my dual HDD RAID array was hooked up to the SATA 3 slots on my motherboard, so to get the OS installed and my data transferred over to it, I just plugged it into the SATA 2 slot. Now that my data is transferred, I wiped the HDDs and un-raided them. I then plugged the HDDs into the SATA 2 slots and the SSD into the SATA 3 slot. I went into the BIOS and changed my drives to run AHCI instead of IDE as well.

I was expecting to see some pretty good increase in performance from the Samsung Magician performance benchmark test when moving from SATA 2 @ 3Gb/s to the SATA 3 @ 6Gb/s but not quite.

SATA 2:

SATA 3:

Why is sequential read up but everything else down when I switched from SATA 2 to SATA 3?

Also, when it was plugged into the SATA 2 I did not set the OS Optimization. Once I plugged into the SATA 3, I had ran the OS Optimization for 'performance' and then ran the Performance Optimization prior to doing the performance benchmark. RAPID mode is off for both.

 

[Dereck47]

If you are using a X58 chipset motherboard then that would explain it.

X58 chipset motherboards do not have native SATA 3 (6Gb/s) ports. They use a Marvell 6Gb/s SATA controller that was developed around the same time as 1st generation SSDs. It doesn't have the bandwidth to handle current generation SSDs.

 

[Imriela]

If you are using a X58 chipset motherboard then that would explain it.

X58 chipset motherboards do not have native SATA 3 (6Gb/s) ports. They use a Marvell 6Gb/s SATA controller that was developed around the same time as 1st generation SSDs. It doesn't have the bandwidth to handle current generation SSDs.

Nail on the head, thanks. i7-930 with an ASUS P6-X58D-E motherboard, which is indeed an X58 chipset. Been considering getting a Z97 to replace it. Would I feel much real world difference in the SSD's performance dropping the money on a new Z97 chipset CPU and Motherboard (been eyeing the i5 4690k with an ASUS Maximus Hero VII)?

 

[Dereck47]

Yes, there would be a real-world performance improvement, but that would also be due to the fact that you're upgrading your cpu as well.

If you were already planning to upgrade your system then go for it.
If you're upgrading just to get the advertised Read/Write speeds from your 850 EVO then it might not be worth it.