wanderer11 :
It will be fine. It is not going to slow down your hard drive. That HDD will not use 6 Gb/s or even 3 Gb/s. The disc drive will run even slower. Sata 3 is a marketing gimmick on HDD and ODD because none can do that speed anyway. To answer your question, a Sata 2 device in a sata 3 port will not slow down the sata 3 device in the other sata 3 port.
I hope you are correct! The large cable supplies specialists site I bought the SATA III (6GB/s) cables from warned that if more than one SATA device is connected to the SATA bus/port that all SATA devices would communicate with the MoBo at the speed of the slowest device. In this case the DVD and BluRay drives are SATA 1 (1.5GB/s). I have an older WD 750GB Black that has a jumper setting to slow it from 3GB/s to 1.5GB/s in case the MoBo SATA was only 1.5GB/s capable. So SOMETHING is going on. I just ordered this upgrade yesterday so in about 10 days I'll get it built (hopefully) and run some benchmarks and post 'em.
I've seen other messages stating that calling a HDD SATA III (6GB/s) is a sales "gimmick", possibly a "scam" which I think would be a crime.
So, to be specific: Are you saying it won't slow other devices because none can communicate through SATA III that speed anyhow or is the company that specializes, for 12 years, in cables wrong about the physical nature of SATA? Or is HDD performance not effected by ODD specs? Would my SATA III HDD slow down if I added a SATA I HDD as a second HDD for more storage?
My old MoBo has SATA II (3GB/s) and when I benchmarked HDD's there was a definate difference in speed with a SATA II HDD running at 3GB/s and then jumpered for SATA I (1.5GB/s) as well as a straight SATA I HDD.
I just now talked to a buddy who recently built a similar machine. According to him BOTH you and the cables people are right! He told me that SATA ports on MoBo are 2 types (3 counting RAID) Primary and Secondary and if I don't want to lose speed to connect all SATA III devices to one and all
SATA 1 or II devices to the other. He also said that to get full advantage of SATA III (6BG/s) that many SSD's are capable of supplying data fast enough to benefit from SATA III (but WAY pricey per GB of storage!).
Seagate Barracuda ST31000524AS 1TB 7200 RPM 32MB Cache SATA 6.0Gb/s after "instant savings" and a "promotional coupon" ended up costing $59 shipped so I guess I got a 1TB drive with a SATA III connection than doesn't spin fast enough to feed it. 1TB of SSD would require 2 512GB drives and $998... Hmm $1 per GB or 6 cents per GB. My wallet says 6 cents. Thanks! I've really gotten rusty since I retired! Also, 6 years since my last "game machine" build. Hope my pair of GeForce 1024MB GTS 250 SLI's will give me another year.
Glossary:
HDD = Hard Disk Drive, ODD = Optical Disc Drive (CD.DVD,BD) SSD = Solid State Drive, MoBo = Motherboard, SATA = Serial ATA, PATA = Parallel ATA (IDE)