Sc card reader speed??

[ivnj]

System Report says my internal sd card reader in my new 2011 mac mini bought on the 23rd from frys is 2.5 GT/s. What is GT/s?? How many megabytes per second is 2.5 GT/s??

 

[eutexian]

System Report says my internal sd card reader in my new 2011 mac mini bought on the 23rd from frys is 2.5 GT/s. What is GT/s?? How many megabytes per second is 2.5 GT/s??

GT/s is Ghz X 2

I believe 2.5 is the standard for SD card reader hardware.

 

[Moriarty]

2.5 GT/s on PCI-Express = 250MB/s

This is how that's worked out... note 'b' = bits, 'B' = bytes, 8b = 1B.

2.5 GT/s = 2.5 Gb/s = 312.5 MB/s... then you've got 8b/10b overhead so 312.5 * 0.8 = 250 MB/s.

 

[ivnj]

Thanks, but I'm not following. What overhead??

 

[Hexley]

Overhead like "noise".

Not bad to know that I can use faster SD cards with it.