Samsung 840 Pro 128GB Too Low IOPS. Why?

[TheCardPlayer]

Hello everyone, just swapped 2 OCZ Vector SSDs that my computer Fried for a Samsung 840 Pro. I thouroughly checked my pc for bad stuff: PSU Thermaltake 80Bronze 750W with multimeter: shows constantly 5.07volts and even under stress. Motherboard: ASUS M5AFX99 PRO R2.0 - System optimised for SSD, on Windows 8 x64, AHCI active, all looks ok.

As it may seem, i have been connecting the 2 Fried SSDs on the Secondary ASMEDIA ports that are not managing the drives corectly and that apparenty fried them after a couple of weeks. Now i got my 840 Pro on the native AMD Chipset ports, WITHOUT the AMD Chipset driver, i read somewhere to avoid it at all costs and use the native MS one.

My results:

Sequential Read 520 (Up to 530) OK
Sequential Write 385 (Up to 390) OK
Random Read (IOPS) 52339 (Up to 97000) ???
Random Write (IOPS) 44391 (Up to 90000) ???

The last two seem to be about half of what i should be getting! I am totally afraid to lose another SSD as i will have to RMA PSU and MOBO just to make sure nothing happens next time, but am i doing anything wrong? Or are these results normal? I have Activated MAximum Reliability on Samsung Magician and also Over Provisioning, doesn't know if this makes a difference... please help...

 

[TheCardPlayer]

Tried installing AMD AHCI Driver. I get about 2000 lower iops. And i cant remove the driver either. xD

 

[TheCardPlayer]

Anyone any ideas?

 

[mortici]

If you have the asrock z77 extreme4 like I do, go into the BIOS and under advanced -> cpu: Disable C1e state, then go under Storage Options and disable SATA power management. Benchmark and see what your results are, then re-enable C1e state, test again. Depending on the results use the c1e setting that gets you the best result.

My results after disabling both: http://i.imgur.com/ZzOP9bR.png