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First Looks At PCI-X, BTX, New Chipsets, And More
rsrsharma writes "AnandTech has some early bird Computex 2004 coverage up its sleeve. Included are the first pictures and partial specs of nVidia's NV45, the PCI-X (PCI-eXpress) successor to the 6800 Ultra, and ATI's PCI-X cards. Also shown are Intel's new 9xx line of chipsets and LGA-755 motherboards, BTX form factor (the successor to ATX) motherboards, and much more. I'm definitely looking forward to this stuff." Update: 06/01 01:08 GMT by T : Several readers have pointed out that PCI-X properly stands for "PCI Extended" rather than "PCI Express."
As usual there's some confusion between PCI-X (64bits PCI up to 133mhz) and PCI express which is a serial bus. Please call that PCI-E or whatever!
PCI-X and PCI-Express are NOT the same thing!
If you don't feel like clicking through a hundred pages, use the "print" link instead.
IIRC, PCI-X is just an extension of the PCI standard up to 133MHz (true PCI-X) with some other protocol tricks. PCI Express is to be a serial standard capable of Gbps speeds (2.5Gbps per channel). PCI - eXpress - I dunno what this is...
I'm quite certain PCI-X and PCI-Express are two totally different things. PCI-X is a 64bit PCI port, that is backwards compatible with PCI. PCI-Express is a whole new device connection port with the goal of replacing PCI, PCI-X, and AGP. Thus, you don't call PCI-Express PCI-X.
- tristan
This is actually the first I heard of BTX, so I immediately flipped to the last page and had a look at the board. I have to say that the thing that bothers me the most about it, is the apparent lack of expansion slots. I only saw one slot, which was probably PCI-X?
I sincerely hope that this does not mean the end of expansion cards. Because if it DOES, I am just going to say goodbye to Windows, and get a Mac. It defeats the main advantage of a PC if I can't upgrade whenever I see fit.
PCI-X and PCI Express are not the same protocol. PCI-X is still a 32/64 bit parallel bus that handles FIFOs a little differently than PCI (i.e. the master can transmit unless the target has enough fifo for a complete transaction). It also changes the timing of the bus to allow for speeds up to 133MHz.
PCI Express is a serial protocol.
AnandTech has a halfway decent article on the spec. Good summary of what it is and who it's aimed at. As I understand it will eventually be mainstream, where ATX will be phased out just like AT was.
I'm assuming you're talking about NICs (I for one need quite a few PCI slots myself for the thing). The newer tower computers (early 2005) will probably have lots of PCI slots, one AGP slot, and one PCI-X slot. Small-form-factor computers will have one of each.
It also kinda irks me when I see that PCI-X will not be in any way compatible with older PCI cards. They ought to change the name. This is a good technology, don't get me wrong; this speed is needed for both the newer video cards and gigabit and 10-gigabit network cards of the future, but when people try to stick in the old PCI cards that their cable/DSL provider gave them into those slots and find that they don't fit, they'll be making a call to the manufacturer wondering why a PCI card doesn't fit in a PCI-X slot.
A bureaucratic nightmare, indeed. Change the name, Mr. Industry, or you'll regret ever inventing tech support.
It should be noted that Mr. Anand mostly focuses on the gaming industry. I knew him back when he was in high school and he only looked at new technology if it would help him get his game on. So for mainstream society and the people who use game consoles instead of PCs, this isn't necessarily news.
I too got yanked in to the PCI-X =/= PCI-Express dupe. I was looking forward to backwards compatability so that companies could just start spewing forth their wares and normal PCI board users could still use them. Plus current cards would still work. Someone in someone's marketing dept needs to be shot. BTW, 'splain those little slots? They remind me of the failed CNR idea. Better yet, for a transition (though more expensive) they could do what they did with PCI/ISA, double the slots PCI next to PCI-Exp.
Nice to see both PCI Express x16 and AGP 8X slots on board at least one of them. I'm looking to squeeze a bit more life out of my AGP based ti4200 before updating to one of the newer video cards in a year or so...
+++ UGUCAUCGUAUUUCU
Eventually, PCI-X will be used for everything. Right now, however, the only cards that actually needs the extra bandwidth it provides are graphics cards, so they'll function like AGP.
PCI-X is a 133mhz bus which is backward compatible with PCI and PCI66.
PCI-Express is a system bus but is more of a networking protocol using high-speed differential signaling (like DVI and SATA) as the physical layer.
PCI-X and PCI-Express are similar only in name (and some similarities in how "config space" is handled). They are really two radically different things.
Upon closer look you'll notice that this particular card has a PCI Express x16 interface, but with no bridge chip. It looks like the rumors of a bridgeless NV45 were true.
I love how people on Slashdot are willing to plagiarize in order to gain a little karma.
This pic shows the inside of the NV45. Look at the paths on the circuit. Instead of going straight from one chip to another they form different loops, turn around etc. Are they trying to make them longer, or equal distance or introduce picosecond delays or what?
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
- PCI-X: 64bits PCI up to 133mhz
- PCI Express: Serial bus, a replacement for AGP (mostly), and for graphics cards (at the moment). What I accidentally called PCI-X (PCI eXpress)in the article. From other articles I've read, it looks like it'll be used for all cards eventually. Although I still think this acronym makes more sense than PCI-E, I guess it'll confuse some people who have actually heard of PCI-X before. I have this wierd feeling that the industry is gonna call PCI Express PCI-X now (it sounds way cooler).
Some other info on PCI Express:- There can be different sizes of slots. All the graphics cards use x16 size slots, while it looks like most other types of cards will use x1 size slots.
- It will eventually become ubiquitous like PCI
- More information in this article.
I'm sure I got something wrong, feel free to correct me.Am I missing something? They've replaced the standard ATA-IDE connectors with Serial ATA connectors, gotten rid of all of the PCI slots, but for some reason kept the FDD drive connector and the parallel port? Most newer motherboards support booting from USB flash device. As for the parallel port, there aren't many devices being sold today that use them and there are parallel-USB adapters available for those who want to use their old printers.
I know this is a pico-ATX board so it's understandable that the PCI slots were removed for space-saving purposes, but if a pico-ATX enclosure can't fit an extra PCI card, why leave room for a floppy drive?
I already have a compaq quad port. Then I have FDDI, GPIB, direcpc, 8port serial, atm155,token ring, arcnet (just got the PCI arcnet, woohoo!), HIPPI, fibre channel, myrinet, and a few others that don't come to mind at the moment. As for ISA, there's localtalk, a GCR floppy controller, omninet, starlan 1baseT, etc. All of which can't be found in PCI versions.
So getting a magam 7/13 pci expansion box isn't enough, I needs lots of both. And it wouldn't hurt to have AGP on top of those (though I could live without that, it's not a gaming box).
PCI Express is not compatible with standard PCI, however PCI-X is (just higher clockspeeds (up to 533) & a 64-bit interface)
The key PCI-X feature is "protocol tricks".
Some wait states are eliminated from the
protocol, providing a nice speed increase
for cheap.
Typically a PCI-X slot is also 64-bit and
can go to 66, 100, or even 133 MHz. The key
feature is the protocol change though.
PCI Express is indeed serial, with 1 to 32
serial links working together. (like RAID)
Just get a Ethernet <-> parallel print server. Then you can still use the printer with any computer that has Ethernet. Plus you can use it with any computer on your LAN without needed an active computer to share the printer
Sapere aude!
PCI Express IS NOT PCI-X.
This has been said 100 times on here at least in the past.
PCI-X is classic old PCI running very fast and 64-bits, etc. As used on server motherboards.
PCIe is the new specification with the tiny connectors for general I/O, and longer connectors for graphics.
There is no limitation on PCIe connectors unlike AGP, apart from the chipset. Each slot is point-to-point, so you need a controller for each one.
Here is a motherboard with two PCIe slots (x4 and x16), a standard PCI slot, and 3 PCI-X slots.
the point behind the BTX formfactor was that it's supposed to help enhance airflow in the computer itself. ATX is nice and all, but most chassis these days are crap. (I'd say they blow, but that's a pun I'd like to avoid.) Sure, they worked back when P2s and K6s were the rage, but they're not anymore, and modern CPUs have far more dramatic cooling scenarios to deal with.
Non impediti ratione cogitationus.
LGA-775 is getting a lot of flak because of reliability rumours. However it will be more suitable for higher clocking processors from Intel and is needed.
PCIe 1x is 250MB/s in each direction. That's enough for a dual Gigabit ethernet card, and each slot gets dedicated bandwidth.
PCIe 4x is 1GB/s in each direction. Eight port GigE ethernet card anyone?
PCIe 16x is 4GB/s in each direction.
(those will be new adjusted megabytes of 10^6 bytes, not 2^20)
Look at the extra space on the motherboard when the 1x slots are used as well - should allow more more on-board goodies or smaller boards.
BTX is Intel's idea. Because of their stupidly hot processors. Looks like it will flop badly.
Dunno what the brown slots are. Thought they might be AMR or CNR or something. They are only test boards though - see the edge connector?
I would hope that if you spend the amount of money that it costs for an Laserjet 4300. You would spring the extra money for the one with the network port. What would be the purpose of buying a Laserjet 4300 if you could only print as fast as a parallel port?
PCI Express is software compatible with PCI and PCI-X, but the physical connection is different. There are already specifications available for PCI Express-to-PCI/X bridge, so you need'nt worry about your "legacy" PCI devices becoming useless after PCI Express' adoption.
Gigabit ethernet needs a faster bus than the current PCI. PCI bandwidth is just a hair over 1 Gb/sec.
FreeSpeech.org
PCI-X = Full-Speed 1.0
PCI-Express = Hi-Speed 2.0
While PCI-X stands for PCI-eXtended, which is just 64 bit (and 133mhz?) pci, this is NOT the technology they are talking about in the article. PCI-X is a very expensive implementation as it requires one controller chip per slot, so you will probably never see this in the desktop market.
They ARE talking about PCI-Express (formerly 3GIO or 3rd Generation I/O), which is a whole new standard, but will remain backwards compatible with any newer PCI (2.2) card. PCI-Express is a serial, point-to-point bus, needing only 4 traces per connection, instead of PCI's 32. It has a theoretical transfer rate of 2.5Gb/s in each direction, tho who knows about real transfer rates. Also, you can stack 'lanes', for slots that need more bandwidth(like the video card slot, which uses 16 lanes afaik), giving you your full-duplex 2.5Gb/s per lane.
It is a packet-based protocol like AMD's hypertransport,and ethernet, and the controller will have a type of 'switch' similar to an ethernet switch for interfacing with all your devices. The advantage of this is your peripherals will, if designed to do so, be able to communicate to eachother directly, wihtout burdening the cpu or memory bus.
Also, PCI-Express is -supposed- to be hot-pluggable or designed with hot-pluggability in mind, but we'll see how well that works in practice...didn't seem to be too hot with serial-ata hard drives.
Hope that helps..
It's easier to fight for one's principles than to live up to them.
...or if you've gone wireless get a wireless print server.
"The only normal people are the ones you don't know very well."
I'll go on and say this then... Macs (new ones) have PCI-X (which as everyone has stated is not PCI express). I saw PCI-X on Xeon boards well before Apple shipped a box w/it.