there seems to be 3 different ways to say sata1 or sata2, my motherboard says nothing about what version it is but just says its capable of 150mb/s? I've been looking into getting a new HD but none of the sata drive out there have a 150mb/s rating instead it's 1.5g for sata1... so on and so on. not I'm wondering if I get one faster than what my motherboard can transfer will it still work and are the cords the same?

Sata I standard speeds are 1.5 Gb/s. That is 1.5 giga bits per second, if you multiply it by 1,000 to bring it to mega bits, then divide that by 8 to bring it to the octal byte, that gives us 187.5 MB/s. Now since SATA is serial, which follows the 8b10b paradigm, which is 8 bits of data per 10 bits being sent (2 bits are probably a stop and start bit), we can then multiply 187.5 by .8, and get 150 MB/s.
This shows, that even the SATA I standard can give out a max of 150 MB/s, which is far more than any single hard drive out now can achieve is sustained throughput. If we double that to 300 MB/s for SATA II, we again, see that it too allows for way more than any drive can dish out. Meaning, that even the SATA I standard is superfluous at the moment.
Meaning, i would not worry at all which standard your drives use.
And yes, SATA I and SATA II are standards that are fully backwards compatible.

Quote: Original post by Jarrod1937
Sata I standard speeds are 1.5 Gb/s. That is 1.5 giga bits per second, if you multiply it by 1,000 to bring it to mega bits, then divide that by 8 to bring it to the octal byte, that gives us 187.5 MB/s. Now since SATA is serial, which follows the 8b10b paradigm, which is 8 bits of data per 10 bits being sent (2 bits are probably a stop and start bit), we can then multiply 187.5 by .8, and get 150 MB/s.
This shows, that even the SATA I standard can give out a max of 150 MB/s, which is far more than any single hard drive out now can achieve is sustained throughput. If we double that to 300 MB/s for SATA II, we again, see that it too allows for way more than any drive can dish out. Meaning, that even the SATA I standard is superfluous at the moment.
Meaning, i would not worry at all which standard your drives use.
And yes, SATA I and SATA II are standards that are fully backwards compatible.

ok that explains everything. and by backwards compatable I mean if i buy a sata II card will it work even though my motherboard only has SATA I speeds?

while we're on the subject how fast in terms of mbits can a 7200rpm drive find and read, generally speaking?

Quote: Original post by freeworld
while we're on the subject how fast in terms of mbits can a 7200rpm drive find and read, generally speaking?

My 320gb Samsung drive does 70+mb/s:

#hdparm -tT /dev/sda
/dev/sda:
Timing cached reads: 5276 MB in 2.00 seconds = 2638.73 MB/sec
Timing buffered disk reads: 220 MB in 3.02 seconds = 72.74 MB/sec

Quote: Original post by lexs

Quote: Original post by freeworld
while we're on the subject how fast in terms of mbits can a 7200rpm drive find and read, generally speaking?

My 320gb Samsung drive does 70+mb/s:

#hdparm -tT /dev/sda
/dev/sda:
Timing cached reads: 5276 MB in 2.00 seconds = 2638.73 MB/sec
Timing buffered disk reads: 220 MB in 3.02 seconds = 72.74 MB/sec

It is worth noting that the spinpoint line from samsung is currently a special case. They have achieved excellent data density, which allows for better overall throughput for the same rpm rating (7200). But most drives have not reached those density levels just yet and will give around 50 MB/s average.

The motherboard and hard drive must be set to the same sata mode (1.5 or 3.0). Usually the motherboard will dictate which mode to use so yours would require setting your hard drive to sata-1.5. Most new hard drives are sata 3.0 and would need to be manually set to sata 1.5 mode to work on a sata 1.5 motherboard. That's what I had to do with mine and just FYI, my hard drive had random crashes and errors before I set it to sata 1.5 to match my motherboard so it 'does' matter.

There shouldn't be a noticeable speed difference between the two modes but you might not be able to use hot-plugging/swapping on a sata-1.5 connector.

Quote: Original post by m3mb3rsh1p
The motherboard and hard drive must be set to the same sata mode (1.5 or 3.0). Usually the motherboard will dictate which mode to use so yours would require setting your hard drive to sata-1.5. Most new hard drives are sata 3.0 and would need to be manually set to sata 1.5 mode to work on a sata 1.5 motherboard. That's what I had to do with mine and just FYI, my hard drive had random crashes and errors before I set it to sata 1.5 to match my motherboard so it 'does' matter.

There shouldn't be a noticeable speed difference between the two modes but you might not be able to use hot-plugging/swapping on a sata-1.5 connector.

Member is correct here. While they're fully backwards compatible, i did fail to mention that you may need to set a jumper on the drive to the correct standard. But this is a pretty straight forward task.