Sound Card Interface

[ketinkrad]

Which is the better sound card interface? PCI Express Interface or PCI Interface.

[USRanger]

PCI Express?  Isn't that just for the video card?

[1701E]

PCI Express?  Isn't that just for the video card?

PCI-E Sound cards are for PCI-E x1 slot, never seen one for a x16 slot.

[Fulmar]

The PCI-E 1x slot offers bandwidth of up to 250Mb/s, while PCI is 133Mb/s.

I have no idea if even top of the line stuff (outside of professional audio) requires that much bandwidth.  I know Creative makes X-Fi cards in both PCI-E and PCI variants.  I can't imagine there being any real performance differences between the two.  I suppose if all your PCI slots were occupied and all you had left was a PCI-E 1x slow, I'd go for it.  Otherwise, whichever is cheaper IMO.

[AirFlyer]

My sound card uses a PCI-E x1 (granted I use it in a PCI-E x16 slot) and it seems to work fine. As far as which is better I don't think it's going to matter with a sound card and I would go with what Fulmar said.

[ketinkrad]

I am surprised the techs out there have not explained which is better?

[Getback]

I use a pci-e sound card. More bandwidth. However, to be honest I really don't know which is best.

[Skuzzy]

Like many things, it will usually depend on the card.  Generally speaking a single lane PCI-E card is going to consume more bud bandwidth for the CPU as the single lane PCI-E card interface is slower than the PCI bus.

[ketinkrad]

PCI is faster than PCI-E?

[Skuzzy]

I guess I should clarify that.  It depends on which revision of the PCI-E standard we are talking about and the speed of the PCI bus we are talking about.

A 66Mhz PCI bus moves data at roughly 266MB/s. 
A single lane PCI-E 1.0 bus moves data at roughly 250MB/s.
A 133Mhz PCI bus moves data at roughly 533MB/s.
A single lane PCI-E 2.0 bus moves data at roughly 500MB/s.
A 133Mhz PCI-X (64bit) bus moves data at roughly 1066MB/s.

Now, that is raw speed.  Overhead is higher with PCI-E due to it being a serial stream, it takes multiple hardware interrupts to deal with 4 bytes of data.  For PCI it is one interrupt per 4 bytes of data on a 32 bit PCI bus.  There is more overhead for PCI-E to convert from/to serial to/from parallel memory bus as well, although that is pretty low.

[Getback]

I guess I should clarify that.  It depends on which revision of the PCI-E standard we are talking about and the speed of the PCI bus we are talking about.

A 66Mhz PCI bus moves data at roughly 266MB/s. 
A single lane PCI-E 1.0 bus moves data at roughly 250MB/s.
A 133Mhz PCI bus moves data at roughly 533MB/s.
A single lane PCI-E 2.0 bus moves data at roughly 500MB/s.
A 133Mhz PCI-X (64bit) bus moves data at roughly 1066MB/s.

Now, that is raw speed.  Overhead is higher with PCI-E due to it being a serial stream, it takes multiple hardware interrupts to deal with 4 bytes of data.  For PCI it is one interrupt per 4 bytes of data on a 32 bit PCI bus.  There is more overhead for PCI-E to convert from/to serial to/from parallel memory bus as well, although that is pretty low.

Sure didn't know that. Just assumed their was greater bandwidth. I guess I was going on the PCI-e theory that video cards had greater bandwidth and not taking into account the bus versions.

[Skuzzy]

Video cards (for the most part) use 16 lanes, not one lane, of the PCI-E bus.  In this case, it is one interrupt per 2 bytes per clock cycle, instead of one interrupt per 8 clock cycles (1 byte).

So far, all the sound cards I have seen using the PCI-E bus, have used only one lane.

The hardware to implement PCI-E is much cheaper than PCI is.

[BaldEagl]

Sure didn't know that. Just assumed their was greater bandwidth. I guess I was going on the PCI-e theory that video cards had greater bandwidth and not taking into account the bus versions.

TheZohan could have told you that.  Surprised he didn't jump in.  He is A+ certified after all.