[kndonlee]

I was reading up on Toms Hardware Guide about serial ATA and according to the site current serial ATA implementations are only available on the PCI Bus, via a PCI slot. What this would translate to is that Serial ATA which rates at up to 150MB/sec would be limited by the PCI bus' 133MB/sec transfer limit.

Has Apple integraded the serial ATA chipset onto the Hypertransport bus allowing free reign of data flow for the new harddrives, or have they implemented it via the PCI bus? Sicne they include PCI-X they could've attached the serial-ata controller onto that bus too.

So question is: Where has Apple implemented the Serial-ATA controller? If on the PCI bus, that would be utterly stupid and not offer any performance advantages over ATA-100. If on the PCI-X bus, what is the theoretical transfer Limit for PCI-X? Or is it directly tied into the Hypertransport Bus... oooh la la....

On another note, Serial-ATA's version II and III are going to up the transfer limits to 300 and 600MB/sec! Can PCI-X handle 600 MB/sec????

If it can, a current G5 investment wouldn't be too bad since you' d be able to get a PCI-X serial ata II or III controller card with new drives and take advantage of the harddrives speed.

For those that could use the speed, the Hypertransport bus, and PCI-X alone are advantages of getting a G5 over a Dual G4 now...

Personally I'd have to say I'd like to wait until a Revision B or C of the G5's before getting one though.

[Eug]

Well, Apple says serial ATA is running on the HyperTransport bus.

Note though that no single serial ATA hard drive will saturate even a PCI bus on its own. That said, if you're hard core and doing heavy duty Gigabit Ethernet file transfers and stuff concurrently, then PCI could prove to be a bit of a bottleneck.

[hmurchison2001]

#7- Serial ATA, Gigabit Ethernet, FireWire, USB 2.0 and optical digital and analog audio are all integrated through two bidirectional 16-bit, 800MHz HyperTransport interconnects for a maximum throughput of 3.2GB per second. No PCI

PCI-X links directly to the System Controller(#4) which handles just the Ram and PCI Bus.

On another note, Serial-ATA's version II and III are going to up the transfer limits to 300 and 600MB/sec! Can PCI-X handle 600 MB/sec???

PCI-X could handle the 300MB SATA but not the 600. It would take one hell of a raid to offer 600MB throughput but in the next Decade I wouldn't be suprised. As Apple and others like Intel have already decoupled as much as they can from the PCI bus I dont think it will be much of a problem in the future.

[CIA]

Even a 10K Rpm Serial IDE drive does not even come CLOSE to satuating ATA-150. Now in a RAID, maybe.
But as the above poster said, imagine the RAID neeeded to saturate a 600? With the exception of VERY specialized applications, even the 300 standard is overkill for 99% of us.
Nice to hear that the controller for Serial-ATA on the mac is not tied to the PCI bus tho. It's so nice to have a decent motherboard in a Mac for once.