SATA2 HDD... 16 or 32mb Cache ?

[Aussie Allan]

 Hi everyone

 So the thought is to add a 3rd (or 4th) Momentus XT drive/s to the array to see what sort of performance gains are to be had with the onboard NAND Flash that these drive contain running in raid 0,1 or 5.....Here's the glitch! I've just found some XT 250 Gb models for 35 quid delivered which means I can grab 4 of these cheaper then 2 of the 500Gb units (I already have two of the 500s)....the only hardware difference is 16mg cache against 32 on the higher capacity units.

  I'm reading a lot of "Cache only matters with slower drives and IDE" ....Anyone have any definitive idea?..... I've got a Highpoint-640 raid card arriving tomorrow and can't make up my mind whether to get 16 or 32cache drives, so its......
1) 4x250/7200 16mb cache-total...1TB with  64mb cache and 16 gb NAND Flash or
2) 4x500/7200 32mb cache-total...2TB with 128mb cache and 16gb NAND Flash.....Mmmmmmmmmmmmmmmm!

 Aussie Allan

[Dark Mantis]

Hi Allan,

To be honest in my experience the cache doesn't make a lot of difference above a certain amount. I bought a couple of Western Digital SATA3 Blacks with 64 MB of cache and because of the Marvell problem I ended up using them  on the Intel SATA2 ports and they hardly behaved any better than the SATA2 versions with 32 MB of cache.

Until then I had always believed that the more cache the better but it would seem that it is not quite the case.

[Aussie Allan]

Thanks for the reply Mantis

 I concur!   hard to believe they still put such a premium on drives with higher cache counts for a negligible performance boost

 I'll do a little more reading today but the 4 smaller drives seem like a good bang for buck investment....a little late but congrats on 8000...your dedication to this forum alone is inspirational......... come-on GIGABYTE! how about a few more SSDs for the Boy!