Does anyone have experience with these kind of cards?

My friend just bought one and I'm looking at ordering too since it's not that expensive ... But looks like some people say ATA133 is not much of an improvement over ATA100, at all. Also i'm worried because, AFAIK, the PCI bus has a theoretical bandwidth of 133MB/s, while another site told me the actual speed is around 127MB/s. Add the fact that as you connect your hard drives through the PCI bus you'll have all the other PCI cards such as network adapters and sound cards sharing the bandwidth. Correct me if I'm wrong.
So now I'm wondering whether replacing my on-mobo 100mhz IDE channels with a 133mhz PCI IDE channel shared with the rest of my hardware would actually reduce performance... or not.

I guess one purpose/advantage for having a ATA133 PCI card in the first place is getting over the 137GB hard drive size limitation that ATA100 has, but as I understand it, if you have WinXP Service Packs installed, this problem is solved anyway.
And I'm only looking for more speed.

As I said my friend just bought a card, I wonder if there is a way to benchmark it to see if there is a difference? He has the same mobo and otherwise almost identical configuration.

better saying up and just getting a new motherboard imo, or just updating later.

I mean beyond the 137GB limit break, but speed wise, I haven't noticed much between them.

Just update your motherboard and get SATA

yeah I got replies from another forum not to do it, and meanwhile I've been reading various benchmarks that say it's definitely not a noticiable improvement at all.
I'll save my cash and stop watching this topic

PCIEXpress is out now, and what with SATA, ATA133 isn't too important