Computer Solutions

I’ve run some tests recently to determine the data rate of various hard drives, card readers and memory cards. Some of the results were rather surprising.

The program I used to test the various media was HDTach available at SimpliSoftware. The free version is enough to test the read speeds.

Here’s a summary of the results (all using USB 2.0 ports unless stated otherwise)

Flash drives varied from 8 to 26 MB/sec (Mega Bytes per second).
A SanDisk Ultra II card was 16 MB/sec connected to PC front panel slot. Same card was 1 MB/sec when connected to printer slot.

Internal SATA drives were 60 to 70 MB/sec with burst speeds of 200 MB/sec.
External USB drives varied from 15 to 23 MB/sec. The drive with a speed of 15 MB/sec increased to 41 MB/sec when connected to a Firewire 400 input.

Memory cards varied from 2 to 15 MB/sec the fastest cards being SanDisk Extreme III CF and SanDisk Ultra 2 SD.

Here is a chart of memory card speeds.

Also, here is a link to a nice article in PC Photo Magazine.

Just as a point of reference, cards rated at 133X define a transfer rate of 20 MB/sec but the fastest I could get when I measured one it was 15 MB/sec. Using actual pictures in a test, the average data rate was 10 MB/sec transferring approximately 700 MB of data.

I just received a Buffalo Drive Combo4 500MB external drive with USB 2, Firewire 400, Firewire 800 and eSata connections. Here are the data transfer rates. The rates are for sustained data transfers, not burst rates.

The eSata rate was measured with the drive connected directly to the motherboard Sata port.

By the way, those old floppies that we once depended on transfer data at only 30 KB/sec or two thousand times slower than our hard drives.