What is a scratch disk? It is used to write intermediate files, like the media cache files, the media cache database, the preview files and possibly the Windows pagefile.
SSD's have a nasty habit in that their write performance deteriorates over time untill they reach their 'stable state'. Trimming does not help here. Secondly, SSD's have a limited number of write cycles in contrast to conventional disks. Once that number of write cycles has been reached, the SSD is dead. Writing a lot of small files to an SSD shortens the life-span and makes it reach its 'stable state'performance very quickly. Not all SSD's are equal and I do not know how the Vertex4 does, but generally the performance degradation is sizable. The Agility3 is not very good in that aspect. This means that the performance gain from using an SSD for scratch disks is marginal at best. Instead of a single SSD, you may be better off with two conventional disks in raid0 for scratch. It will be equally fast, possibly even faster and last a lot longer than a SSD and may also be cheaper.
Do not be lured by the marketing hype of some SSD manufacturers about the fabulous writing speeds, sometimes claiming speeds of 400-500 MB/s. In practice and after reaching its 'stable state' is is more often in the order of 300 MB/s or even less. The Agility3 may even top off at around 200 MB/s. Your i5 CPU will have more limitations on your performance than the possible use of a SSD for scratch.
I was afraid that bringing up this question again would be frowned upon, so i sincerely appreciate this helpfull answer!
I will definatly just buy a WD black then. I didnt know that degradation of the agility 3 was something to worry about, so you have probably increased it's lifespan since until now i have used it for scratch files as well as OS and programs.
Would you agree that this would be a balanced system? One ssd for OS and programs, a spinpoint f3 for media files and a WD black as scratch disk. i5-2500k cpu and 16gb ram.
That sounds like a good disk setup. What video card do you use?
I have a gtx 560 ti.
[moved to hardware forum]
I have finally put together the new system:
16gb 1600mhz ram
Spinpoint HDD 500GB for media files
hitatchi 2,5" HDD 60GB for scratch files (temporary)
agility SSD 120GB for OS and programs
However, the playback on the timeline is very choppy, especially after fast-forwarding it stutters for a while. I've tried using the ssd as scratch disk, but it didnt make any difference. Could it be a driver or codec issue?
Sorry about that, heres the complete list:
-Premiere pro CS5.5.2 v/latest updates
-Windows 7 pro (fresh install v/important updates)
-h.264 in mp4-container
-no error messages
-very choppy playback after "jogging" or when theres a lot of movement
-no extra codecs or similar is installed.
-nvidia gtx 560 v/latest drivers
-i5 2500k @ 4,5Ghz(stable)
-16Gb 1600mhz xmp ram
I should also mention that i didnt have this problem on my previous system with the much weaker phenom 965 and 7gb ram. I have also tried using the SSD as scratch disk, but there where no difference at all. I also tried using 1/4 playback resolution, didnt help at all.