Reading while Writing on SSDs vs HDDs

Question

So, I've always heard that reading and writing to an HDD is not good, as it slows down the whole process (this is in video rendering for Premiere Pro).
So, I know that SSDs are quite a bit different.  I'm assuming that reading and writing occurring on 1 SSD during rendering isn't going to be nearly as much of a problem as it would be happening on 1 HDD.  However, I'm unsure of this.  Am I correct in my assumption?  If not, what kind of performance degradation might occur, would it be noteworthy, and how comparable would it be to that of an HDD?

Answer 1

Yes, in addition.....current high quality SATA III SSDs that have the best controllers in them  for video editing, ( like the Crucial M550, or, the more expensive Samsung 850pro), will not suffer from "fill degradation"....losing performance as the drives becomes more full. Also, the RELIABILITY ....especially on the Samsung 850 Pro....is WAY higher for the SSDs, than mechanical spinning drives.....allowing those quality SSDs to be considered for RAID 0 usage with a much lower risk.
What you are getting at is the nature of the SATA interface itself......it is a "half-duplex" interface, which means it CANNOT write while READING...and vice-versa. It's like an old walkie-talkie radio....when you push the button to speak and transmit...you cannot RECEIVE anything ,until you let the button go. So, YES ,that "half-duplex" handicap is still there.....BUT, SSDs reduce its effect with their MUCH faster read and write speeds AND their drastically lower "latency", as Eric has said.
There ARE places to connect storage devices, especially on the new Haswell E X 99 motherboards, which are "full duplex"...allowing reading and writing at the SAME TIME.  However, the storage devices to take advantage of this higher speed and full duplex connection currently are much more expensive than SATA devices. M.2, , SATA "Express", and PCI card storage devices can be used.....but, currently at high expense and limited capacity.
With X99...one option is to take advantage of the huge amount of SATA !!! ports on the motherboard and just create RAID 0 with SSDs for storage..or, use cheaper HDDs, with a large "enterprise level" 7200rpm HDD to BACK UP the HDD RAID0 array !