Making an external HD with a 7200RPM 2.5" disk

[wey97]

I bought an enclosure, slapped in a 7200RPM Hitachi laptop harddrive and it runs great, super fast and not very hot.

My question is, why is no one really offering prepackaged external HDs in 2.5" at 7200RPM? Heat? Power Consumption? Hitachi states the 7k100 has power consumption about like a 5400RPM drive.

I can build my own 7200RPM for about the same price as I can get a pre-built 5400RPM.

Another thought. Will USB 2.0 bottleneck the I/O so writing to a 5400RPM will be just as fast as a 7200RPM?

 

[rvnguy]

Question 1 - Margins

Question 2 - USB 2.0 at 400KB/s is 4 to 8 times the rate of a HD. USB is not the bottleneck here.

rvnguy
"I know everything..I just can't remember it all

 

[wey97]

What do you mean by margins?

 

[rvnguy]

Profit Margins....

rvnguy
"I know everything..I just can't remember it all

 

[wey97]

Are you sure about the speed you quoted? This is the answer I got from another forum...

USB 2.0 support transfer rates up to 480 Mbps (or about 60 MB/s). A standard ATA100 drive supports up to 100 MB/s. You can see a great speed disadvantage there. USB is about 40% slower than IDE.

 

[wahnula]

http://www.answers.com/main/ntquery?s=USB 2.0&gwp=16

USB 1.0 and USB 2.0

USB has a maximum bandwidth of 12 Mbps for USB 1.0 and 1.1 and 480 Mbps for Hi-Speed USB 2.0.

http://www.answers.com/main/ntquery?s=ATA+100

Ultra ATA

An enhanced version of the IDE interface that transfers data at 33, 66 or 100 Mbytes/sec. These enhancements are also called "Ultra DMA," "UDMA," "ATA-33," "ATA-66," "ATA-100," "DMA-33," "DMA-66" and "DMA-100." See IDE for all the ATA types and speeds.

http://www.answers.com/topic/mb-sec?method=5

MB/sec

(MegaBytes per SECond, MegaBits per SECond) One million bytes or one million bits per second depending on whether the B is upper case or lower case. However, using "B" for byte and "b" for bit is not always followed and often misprinted. See space/time.

Upper Case "B" for Bytes

MB/sec, MBytes/sec, MB/s and MBps means megabytes per second and is used for disk and tape transfer ratings.

Lower Case "b" for Bits

Mb/sec, Mbits/sec, Mb/s or Mbps means megabits per second and is used for transmission speeds in a network or in internal circuits.

So, upper case "B" = lower case "b" X 8. But not all the time.

Clear as mud???

 

[wey97]

Yeah that makes perfect sense. I don't know where the 400KB/s came from but USB 2.0 is 40% slower than an IDE HD.

Thanks