I am looking to buy a SATA PCI card and a USB2 PCI card. How is PCI fast enough for these devices?

Question

I have seen Firewire 400 and 800 pci cards, plus SATA and SATA-2 pci cards. However, I thought that PCI only transfer a maximum of 266/mb a sec, whereas these interfaces are much quicker. How does this work and is there a bottleneck/speed decrease when using such cards?

Answer 1

PCI bus max is 133 MB/sec. USB 2 max is 480 Mbits/sec or 60 MB/sec, so no problem. Hard disk external data transfer rate max this year ## appears to be less than 70 MB/sec at 7200 RPM. So, again, not much of a problem unless you want best performance from two drives at the same time, like for RAID.

## SATA 2 disk measured DTR max 243 MB/sec from disk’s buffer (16 MB), only of real use for random access or repetitive reading when data is there rather than in Windows memory based file cache.

Roy

Answer 2

You are right to point out that the bandwidth of many PCI buses can a limiting factor causing bottlenecks, especially the older 32bit versions. If you have an older MB, you have to watch this.
But in reality, you do not achieve the theoretical speed with the 1394 800, or even with the 400, nor with SATA2 devices. As electro-mechanical devices, with SATA2 drives you can expect something like 70MB/sec, even when controllers are directly linked with the Southbridge-interconnect.

Answer 3

Any SATA device will outspeed a firewire;
I discovered this the hard way; And I confirmed this with techs at work. SATA Cards for adding on board Drives and other devices are the pick for fast Production machines, and this seems so for the regular machines. No Limit, in regards to Bottlenecks has been noted in what I have seen at work