[UnixMac]

What's the difference if not?

Thanks

[reader50]

It's not. PCI-X is really just PCI running at a higher clock speed. PCI-E is a packet-based bus setup, and is far superior to PCI or PCI-X. It allows more slots, as well as far faster slots.

If you want a more detailed run down on PCI-Express, look here.

[Catfish_Man]

Originally posted by UnixMac:
What's the difference if not?

Thanks

PCI-E is going to replace PCI-X, PCI, and AGP in theory (and as far as I know theory is pretty close to practice so far).

[hmurchison2001]

PCI Express is sexier.

[OreoCookie]

Right now, there are very, very few PCIe cards on the market. Once, the first PCIe graphics cards are available, things will change, of course. They are due this year AFAIK.

That's why you haven't seen them in the new PowerMacs yet. My guesstimate is that Apple will include PCIe in their next CPU upgrade if things work out fine.

[Busemann]

The fact that it is not backwards compatible is the major con though

[OreoCookie]

Yes and no. Most PC mobo manufacturers solve this by adding a PCI slot. But the future is definitely PCIe. Why? Because of graphics cards, they need the extra bandwidth and the extra power.

[Machster]

Originally posted by reader50:
It's not. PCI-X is really just PCI running at a higher clock speed. PCI-E is a packet-based bus setup, and is far superior to PCI or PCI-X. It allows more slots, as well as far faster slots.

If you want a more detailed run down on PCI-Express, look here.

That arstechnica article mentions that PCI-X is highly susceptable to noise:

"The faster a bus runs, the sensitive it becomes to noise"
"The higher clock speed isn't the only thing that increases PCI-X's noise problems...Because the bus is wider and consists of more wires, there's more noise in the form of crosstalk."



Could this be the cause of the noise problems some users have reported on some G5 units?

[Catfish_Man]

Originally posted by Machster:
That arstechnica article mentions that PCI-X is highly susceptable to noise:

"The faster a bus runs, the sensitive it becomes to noise"
"The higher clock speed isn't the only thing that increases PCI-X's noise problems...Because the bus is wider and consists of more wires, there's more noise in the form of crosstalk."



Could this be the cause of the noise problems some users have reported on some G5 units?

Noise in the electrical sense is not the same as noise in the sense most people think of it. It's more like static on the wires, makes it harder to send data, but it's nothing you can hear.

[eddiecatflap]

PCI-E is the ONLY reason i'm waiting to upgrade


can i be alone ???

[Machster]

Originally posted by Catfish_Man:
Noise in the electrical sense is not the same as noise in the sense most people think of it. It's more like static on the wires, makes it harder to send data, but it's nothing you can hear.

Perhaps it was then a poor choice of words on the part of the author? "Crosstalk" refers to something that can be heard (edit) in the audio chain.

[bighead]

Originally posted by eddiecatflap:
PCI-E is the ONLY reason i'm waiting to upgrade

can i be alone ???

Yes.

[Catfish_Man]

Originally posted by Machster:
Perhaps it was then a poor choice of words on the part of the author? "Crosstalk" refers to something that can be heard (edit) in the audio chain.

Not quite sure what you mean by "the audio chain" (and you could very well be right), but I understood crosstalk to be interference caused by induction between nearby wires.

[Machster]

Originally posted by Catfish_Man:
Not quite sure what you mean by "the audio chain" (and you could very well be right), but I understood crosstalk to be interference caused by induction between nearby wires.

When I began researching the purchase of a G5, I found many reports of noise coming from the analogue output. Some audio professionals reportedly have stayed away from them until the problems are solved. There were also reports about what is the now infamous "chirping" sound, which has been thought to be a power supply and/or logic board defect. Audio crosstalk, where electrical component noise might leak into the audio jacks might be what the article was referring to...but it is too vague in its description.

Some posts in this forum also reported that the 1.6Ghz model did not have this problem. This would lead me to suspect that the PCI-X might be the source since the 1.6Ghz lacked that feature.

[Catfish_Man]

Originally posted by Machster:
When I began researching the purchase of a G5, I found many reports of noise coming from the analogue output. Some audio professionals reportedly have stayed away from them until the problems are solved. There were also reports about what is the now infamous "chirping" sound, which has been thought to be a power supply and/or logic board defect. Audio crosstalk, where electrical component noise might leak into the audio jacks might be what the article was referring to...but it is too vague in its description.

Some posts in this forum also reported that the 1.6Ghz model did not have this problem. This would lead me to suspect that the PCI-X might be the source since the 1.6Ghz lacked that feature.

Interesting. I hadn't thought of that explanation for the noise, but it seems possible. Anyone with a G5 care to track down the audio and PCI-X circuitry on their mobo and see if they're reasonably close together?

[reader50]

The 1.6 and original 1.8 (single CPU) G5s use a lower-capacity power supply. The duals use a higher-capacity power supply in the same-sized space.

Seems like all the power supply noise complaints come from people with the duals, and Apple seems to agree - they have been trying to fix it with revisions to the power supply.

[Machster]

Originally posted by reader50:
The 1.6 and original 1.8 (single CPU) G5s use a lower-capacity power supply. The duals use a higher-capacity power supply in the same-sized space.

Seems like all the power supply noise complaints come from people with the duals, and Apple seems to agree - they have been trying to fix it with revisions to the power supply.

If I am correct that the 1.8 single did have PCI-X then the following holds true:

If there are no noise problems with the 1.6 but some with the 1.8 then the PCI-X remains a question mark.
If there are no noise problems with either then my PCI-X theory loses some validity.

[Peter]

Originally posted by hmurchison2001:
PCI Express is sexier.

[eddiecatflap]

in 18 months , when you want to upgrade your videocard , everyone will be on pci-express

pci-x is a waste of space

[olePigeon]

Originally posted by Busemann:
The fact that it is not backwards compatible is the major con though

It is backwards compatible, just requires an adapter for the pins.