which drive ?

[wingfan]

of the 2 which would perform better.. overall performance (faster)?

Western Digital Caviar (WD6400AAKS) 640GB SATAII 7200RPM 16MB Buffer $75 CDN
Western Digital Caviar Black (WD5001AALS) 500GB SATAII 7200RPM 32MB Cache $80 CDN

price is $5 more for less GB yet double the cache. i dont really mind the 140GB more space.. but is the 32 vs 16 mb that big of a difference? if not i will go with the more GB.

[redwudz]

The 32MB cache one might help a bit with data transfer, but for most editing, encoding, playback, probably no noticeable difference, IMO.

WD seems to think cache size is important, but the two drives you listed are different series. The 640 is a 'Blue' drive, or just a normal drive. The 500 is a 'Black' drive, or their premium model. There are also power saving drives in the 'Green' series. From WD:

Cache memory is the data buffer or cache between the hard drive and the actual platters in the drive where data is temporarily stored. Access to data in the memory cache is much faster than accessing data on the platters in the hard drive. The larger the memory cache, the more data can be stored which can be accessed faster. A drive with 16 MB of cache will perform faster than a drive with 8 MB or 2 MB of cache because more data can be stored in the cache on the 16 MB cache drive.

But this may just be advertising hype instead of real information. The drives are difficult to compare as they are different series, so actual specs would differ, even withot the larger cache.

There is a larger cache in the computer itself that the system uses to cache/buffer hard drive data and that probably is used more than the on-board HDD cache.

HDD acess times, tranfer times and the rest depend more on the SATA controller than the HDD itself.

With all that said, I would probably go with the 500GB drive because it's a 'black' series and should have better dependablility. (And there is a 640GB 'Black' SATA drive.)

[neomaine]

The 32MB cache one might help a bit with data transfer, but for most editing, encoding, playback, probably no noticeable difference, IMO.

Absolutely correct. With a sustained transfer rate at @60MB/sec, it would take how long to fill the drive cache? Yup, about 1/2 second. Anything after that is direct i/o.

Cache memory is the data buffer or cache between the hard drive and the actual platters in the drive where data is temporarily stored. Access to data in the memory cache is much faster than accessing data on the platters in the hard drive. The larger the memory cache, the more data can be stored which can be accessed faster.

Again 100% correct, buuuuuuuutttt ... see above.

A drive with 16 MB of cache will perform faster than a drive with 8 MB or 2 MB of cache because more data can be stored in the cache on the 16 MB cache drive.

It will only perform faster IF it can use that cache. For small repeatable reads this can be very helpful. Almost anything done with video is neither small nor repeatable.

Though, you didn't mention what the purpose of the drive would be. RPM is much more important here than cache size. A 10k RPM drive would give you a better sustained xfer than a 7200 RPM drive at about 20% for large reads and/or writes.

Again, assuming the drive is used mostly for large files, you can also help things out by using larger cluster sizes when you format the drive. Yes, there is a minimum file size and smaller files (anything smaller than the cluster size) will use more space then necessary, but this will cause fewer reads to have to be made. Use 32k instead of the default 2k or 4k.

Not that I implement everything on the following link, but I agree with everything on this page except for #4 (use more partitions) and #10 (seperate drive for pagefile) except in specific situations.

http://www.windowsdevcenter.com/pub/a/windows/2005/02/08/NTFS_Hacks.html

[jagabo]

Of those two drives the one with the higher density platters will be faster. If you're using it mostly to store lots of video file it doesn't really matter which is faster. I'd just go for the bigger one.

[budz]

The WD Black series hard drives carry a 5 year warranty where as the green drives only carry a 3 year warranty. IMHO get the Black series.

[edDV]

Even a 32MB cache is tiny for video data. For capture, edit and encode any recall is done mostly from system RAM then maybe some page reads to temp files. Most of these reads are far greater than 32MB.

Disk cache may help a text, doc, or even audio web server where many users repeat ask for the same data, but is of limited benefit for relatively huge video files.

[wingfan]

i went with the 500GB 32 MB, thanks!