PCI, PCI-X, and PCI-Express

[Starks]

Basic PCI Bus Specifications

33.33MHz clock with synchronous transfers
peak transfer rate of 133MB per second
32-bit bus width
32-bit address space (4G bytes)
3.3 volt or 5 volt signalling
reflected-wave switching

Basic PCI Variants

PCI 2.2, allows for 64-bit bus widths and/or 66MHz signalling (peak transfer 533 MB/s)
PCI-X, 64-bit version of 2.2 that increases the data rate to 133MHz (peak transfer 1066 MB/s)
PCI-X 266 (or PCI-X DDR), "double-pumped" PCI-X for 266MHz rates (peak transfer 2133 MB/s)
Mini PCI
Compact PCI, uses Eurocard-sized modules using PCI as a backplane

PCI-Express

PCI-Express (formerly known as 3GIO for 3rd Generation I/O) is a new implementation of the PCI computer bus that uses existing PCI programming concepts and communications standards, but bases it on a much faster serial communications system. It is being supported primarily by Intel, who started working on the standard as the Arapahoe project after pulling out of the InfiniBand system.

PCI-Express is intended to be used as a local bus only. Due to it being based on the existing PCI system, cards and systems can be converted to PCI-Express by changing the physical layer only – existing systems could be re-booted on PCI-Express and never even know it. The higher speeds on PCI-Express allow it to replace almost all existing internal buses, including AGP and PCI, and Intel envisions a single PCI-Express controller talking to all external devices, as opposed to the current northbridge/southbridge solution in current machines.

PCI-Express is not, however, fast enough to be used as a memory bus. In this respect it is at a distinct disadvantage to the similar HyperTransport which can be used for this role as well. In addition PCI-Express does not offer the flexibility of the InfiniBand system, which has similar performance, but can be used for both internal and external buses.

[nm+]

BTW, PCIe is the abbrevation of pci-express

[Starks]

This should be stickied...

[nm+]

I was thinking the same, for now at least, too many people getting pci-x and express confused

[NAJMI ADNAN]

Originally posted by nm+
I was thinking the same, for now at least, too many people getting pci-x and express confused

Nope not me......

[Starks]

PCI < PCI-X < PCI-Express

[maxjhk]

So the on the mobos we have rite now is PCI-X rite, or are they just used for server mobos?

[videobruce]

Just what we need, another card format!

[V_LESTAT]

if the hypertransport can be used in a wider range of applicable hardware(s) and is faster(i think you said it was faster)
then why havent we seen this used with video cards like they are doing with pci express ati and nvidia cards ?

wouldnt it be feasable to assume that a second hyper chip could be put on the mobo and used soley for video/agp thus removing the need for a pci express card to work parallel with the video card.. ?

same thing with network interfaces, pump the data thru the network,, since both your netowrk, AND hard drives are capable of speeds faster than current network speeds, this would allow in house OC43 type lines or OC12 with no upgrades needed to your current hardware other than possibly a pci express card. or a new system with this technology.

on a netowrking side note. if your familiar with the xbox dashboard "AvaLaunch" it uses a burst mode programming that allows for a true 10meg/sec and up transfer rates from your pc to your xbox and also xbox-xbox. (mine usually levels out at right around 11,000 kb/sec) where as most 10/100 netowrks would only push 5-6 megs per second.
this is with a standard 10/100 lan.
the gentleman a few weeks back released the source code for this and i wish we'd start seeing some PC applications implement this. much fast LAN transfer speeds, 2-3 times faster
sorry off topic.


i am eager to see what the true real world results of pci express will be when implemented with ati and nvidia cards.
the new games and such could implement worlds and graphics of such detail that we have never seen before. worlds with more cars and people and buildings and trees onscreen at the same time than any other platform ever.

i hope, meaning is this what i am to understand Express would allow prorammers to do ?

[heffeque]

hypertransport connects other things, like CPUandCPU, CPUandNorthbridge, etc... if they could make hypertransport available for vid card management, they would, I promise you also.. hypertransport has variable Hz speed and video cards don't suport that.

[RandyB]

Originally posted by heffeque
hypertransport connects other things, like CPUandCPU, CPUandNorthbridge, etc... if they could make hypertransport available for vid card management, they would, I promise you also.. hypertransport has variable Hz speed and video cards don't suport that.

I get the impression by your sig that you enjoy the occasional cigarette and drink.
BTW: I think the new PCI-E is going to be a good thing.

[Doomster]

Good thing yes but what will the cost to us be......in time and money upgrading..........if your system is fast now why change your system just because it's new.........will present-day applications take advantage of this new technology.....I doubt it....everything will have to be rewritten.........right now the computer market is stagnant......there is nothing new (in terms of technology)........so expect another two years for programmers to catch-up