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Issues with SSD and HDD x2 RAID0 Configuration with "6Gb/s" SATA Marvell chip

sorab

Honorable
Apr 24, 2013
4
0
10,510
Hi community :)

So I have found myself in a bit of an unfortunate situation, and am here to seek advice on how to fix/improve things

My setup is as follows:
GA-Z77X-UP5 TH
samsung 840 proseries 128GB SSD 6Gb/s
2x wd caviar black 1tb 6Gb/s


The SSD as main boot drive, and the HDD in RAID0

Makes sense so far, yes?

Well, the issue as it turns out is with the SATA 6 Gb/s connectors on the MB...

When specs said 3x SATA 6 Gb/s, I assumed it was as clear cut as that.... no...
What I found out is that one of these ports, the one on the Marvell 88SE9172 chip, does not support TRIM, now I am not 100% on whether it's just that Marvell don't have TRIM drivers, but from what I gather, regardless of this, SSDs suffer in performance on this connector on the board...

So option 2 is use it for the RAIDed HDDs... No again... Apparently since this connector is connected via PCIe bus, it hits some kind of bottleneck performance issue...
http://forums.adobe.com/message/5133633

Anyway, if all this is fact, it kinda hurts to realize that I will have to run 6 Gb/s drives on SATA 3 Gb/s.... I guess it's not too bad, since performance is quite close, looking at benchmarks between the two, but I could save a few pennies where the upgrade seems to be obviously redundant... right?
http://www.tomshardware.com/reviews/ssd-upgrade-sata-3gbps,3469-4.html

So, should I replace my SSD with a cheaper 3 Gb/s, or do you see another reasonable option in here somewhere

Any advice is welcome!
Thanks guys!
 
Solution
Connect your Samsung 840 Pro to one of the Intel SATA 6Gb/s ports (SATA3_0 or SATA3_1).
Connect your WD Caviar Blacks to the Intel 3Gb/s ports (SATA2_2 & SATA2_3).

HDDs can be 6Gb/s "compatible", not 6Gb/s "capable".
No HDD can spin fast enough to achieve 6Gb/s speeds.

The 1TB Western Digital Caviar Black has sustained Read/Write speeds of 126MB/s, which is actually SATA 1 (1.5Gb/s) speeds.
The 64MB Buffer in the drive can transfer data at 6Gb/s speeds, but that's it.
http://www.wdc.com/wdproducts/library/?id=350&type=8
Put the 1TB Blacks on the Intel SATA II ports, voila, done.

Unless something has changed substantially there were no mechanical HDD's that could sustain saturation of a SATAII port, it (as far as I know) is only possible when moving files from the HDD's cache, which isn't going to be for long (64MB cache / 300MBps = 1/4 second).

Thus keep the high end SSD you've got on the intel SATAIII port and make the best possible use out of it and put the HDD raid array on intel SATAII ports. I'd guess you wouldn't see much of a difference in benchmarks before/after moving the array.
 
Connect your Samsung 840 Pro to one of the Intel SATA 6Gb/s ports (SATA3_0 or SATA3_1).
Connect your WD Caviar Blacks to the Intel 3Gb/s ports (SATA2_2 & SATA2_3).

HDDs can be 6Gb/s "compatible", not 6Gb/s "capable".
No HDD can spin fast enough to achieve 6Gb/s speeds.

The 1TB Western Digital Caviar Black has sustained Read/Write speeds of 126MB/s, which is actually SATA 1 (1.5Gb/s) speeds.
The 64MB Buffer in the drive can transfer data at 6Gb/s speeds, but that's it.
http://www.wdc.com/wdproducts/library/?id=350&type=8
 
Solution
That's great! Thanks for the quick and very helpful responses :)

So you don't think that these HDDs are overkill on SATA2 connections? From what I understand, it still 'technically' outperforms the '3Gb/s' HDDs, yes? ... I mean I shouldn't exchange them for 3Gb/s to save a few dollars