Quick Question.. what is UDMA mode 5?

[Mamapajama]

Just as the question asks.. by the way.. can someone also explain "PIO mode 4" and all the other modes listed during boot-up? Is UDMA 5 the same as ATA-100?

 

[jimmygates]

UDMA 5 is ATA 100.


I'm not sure but I think PIO 4 = 16MB/s?



-jimbo

 

[Ferretwulf]

Yes, PIO Mode 4 is 16.6

 

[Noriaki]

PIO = Programmed I/O mode. PIO4 is 16.6MB/s but more importantly it's all CPU controlled I/O transactions.

(U)DMA (aka (U)ATA) is direct memory transfer, and thus goes straight from the Disk controller to memory. It doesn't involve the CPU directly in the transfer.

UDMA Mode 1 = 16.6MB/s also.
UDMA 2 = 33.3 MB/s (aka UATA 33)
UDMA 3 = 44 MB/s
UDMA 4 = 66.6MB/s (aka UATA 66)
UDMA 5 = 100MB/s (aka UATA100)

 

[pezdude]

Whats UDMA 3 for?

 

[Noriaki]

I have no idea...I've never seen it used.
But it's specified...everything when from mode 2 straight to mode 4 (ATA33 to 66).