Hi, I think I am trying to measure data transfer rate from harddisk. I have read UDMA-mini-HOWTO on LDP site and it also said "UDMA drives will give you between 10 and 15 MB/s using UDMA mode 2 (33 MB/s) or 4 (66 MB/s) enabled". If the DTR never gets higher than 33MB/sec then why use DMA-66, since there is no performance improvement? How come benchmark under Win98 gave me DTR of DMA-66 drive 2 times of normal DMA-33 drive? Am I misunderstanding something here?
Confused Vachi ----- Vachirasuk Setalaphruk ISE, Osaka University From: "Stephan Hachinger" <[EMAIL PROTECTED]> Subject: Re: no merit from using DMA-66? Date: Sat, 18 Mar 2000 21:35:53 +0100 > Hello! > > Are you really sure you're measuring the maximal bus speed? > > Because the bus speed (UDMA33=33MB/sec; UDMA66=66MB/sec) is only the maximum > data rate which can be transferred. However, the magnetic disk can never be > that fast, so that data rates of 16MB/sec are quite normal and not bad. > 25MB/sec must be a very good hard disk. So, just don't worry, this high data > rates can only be reached if the data comes from the HDD cache over the bus. > > Kind Regards, > > Stephan Hachinger >
