64mb sas drive cache vs 16mb

trying to make up my mind on either ultrastar600 15k sas 600gb or cheetah 15k 6oogb both drives 6gb/s sas.
ultrastar 64mb cache cheetah 16 mb cache.....cheetah 200+ mb/s transfer
ultrastar 195+ mb/s transfer.......only using 1 sas drive for windows, Atto HBA, no raid at all.

heres a little what they say on these drives:
The Ultrastar 15K600 delivers an impressive 195 MB/s throughput. Only Seagate’s latest Cheetah 15K.7 is a bit faster, delivering over 200 MB/s. Write throughput is similar and maintains minimum transfer rates of 116 MB/s. If you only use two of these hard drives in a RAID 0 setup, you will already beat every SSD when it comes to sequential writes, and most likely you’ll also beat the SSD in total price if you go for smaller capacity versions.

Other performance metrics, such as application performance and I/O performance have increased by a considerable margin. Access time decreases. Power consumption hasn’t decreased at idle, but it was optimized a bit under certain workloads. In the end, this drive provides much increased performance per watt when it comes to high I/O activity and largely improved performance per watt for streaming workloads
besides saying get a ssd i have that already, im hooked on scsi and sas
for navagation and opening programs, internet what drive would be fastest here......thanks

Why on earth are you looking at 15k rpm enterprise SAS drives? Don't waste your money; save your money for a third-generation SSD instead. These HDDs are useful for specific circumstances only and certainly NOT desktop usage!

Get a SAS SSD if you like the SAS interface that much (the only real change is being full duplex on the command channel; boo-hoo for a serial HDD device!)

Buying a 15k rpm enterprise HDD as consumer - at this year - is just complete nuts IMO. Not intending to offend you, however. But i can't see any valid reason to spend your money like this; its a complete waste.