PCI Express

mick70 · 08-07-2004, 22:08

Recommend anyone thinking of buying a new pc waits a while till pci express is released into the mainsteam later this year. AGP graphics cards will look like like clockwork!

swoop101 · 08-07-2004, 22:18

I agree that it is best to wait.
Looking at the first write-ups the new system will be very fast, but it will be a very extensive and expensive upgrade.

Personally I would wait at least 12 months.

Dave Stones · 08-07-2004, 22:26

the dell dimension xps uses pciX cards, looks promising for a dell if a little expensive

i would hold off until the price levels a bit...

Tristan · 08-07-2004, 22:32

I'm planning to wait 18 months or so, then do a big upgrade to a 64-bit, PCI-X type system, BTX motherboard/case etc...

With a bit of luck, prices, availability, drivers and software should all have converged by then.

greencreeper · 08-07-2004, 23:04

I can remember when it was all simple - main choice was whether the CPU had a maths co-processor or not. Now a days it's all acronyms and complex compatability issues

Tristan · 08-07-2004, 23:25

Complex compatability issues? It's easier to build a PC today than it ever has been. It's just a matter of putting the bits in the only holes they'll fit in. The only bit that's tricky is setting master/slave/cable select jumpers on IDE drivers, and SATA is going to get rid of that anyway.

Oddly, part of me longs for the days of the ISA bus and resolving IRQ conflicts in DOS...

greencreeper · 08-07-2004, 23:32

AGP? Now you 1x, 2x, 4x and 8x. Also have version 1.0, 2.0 and 3.0 (last time I checked) of the specs. A 2x slot can be 1.0 or 2.0 - some cards won't work with 1.0. This is simple?

Give me an IRQ conflict any day. Not just DOS - my mum's laptop has one and it's a modern machine running Windows ME (I didn't install it).

ZrByte · 09-07-2004, 00:05

Quote:

Originally Posted by greencreeper

AGP? Now you 1x, 2x, 4x and 8x. Also have version 1.0, 2.0 and 3.0 (last time I checked) of the specs. A 2x slot can be 1.0 or 2.0 - some cards won't work with 1.0. This is simple?

Give me an IRQ conflict any day. Not just DOS - my mum's laptop has one and it's a modern machine running Windows ME (I didn't install it).

And how many people still have an AGP 1x 1.0 motherboard that would even be worth putting and AGP 8x 3.0 card in??

FYI the last agp 1x v1.0 mobo was a 4x86 upto DX4 120, and the minimum agp 8x card is a GF4MX, a machine that low-end probably doesnt even have the processing power to run the drivers for that hardware. :p

Edit: and on topic, ive been holding out on any modern upgrades to my PC for quite some time.
Once the prices come down a little and software becomes a little more supportive to the new hardware I plan to buy....
64bit CPU
PCI-Xpress mobo
Sata hdd's
and im also thinking of a gigabit LAN for the wired part of my Wired/wireless network.

greencreeper · 09-07-2004, 00:14

Quote:

Originally Posted by ZrByte

And how many people still have an AGP 1x 1.0 motherboard that would even be worth putting and AGP 8x 3.0 card in??

Mine has a 2x slot - can't remember if it's 1.0 or 2.0. I think it's 2.0. Card is a Voodoo 3 - they don't make them or the drivers anymore

I looked at buying a new card and I tried a couple but didn't like them, so I stuck with the Voodoo. I had a nightmare time trying to find cards - some manufacturers just don't produce any information on their cards, and retailers are just as bad. I needed to know which cards where compatible with my system - two different cards with the same chipset would have different compatability specs. I found it difficult - a newbie wouldn't have a hope in hell, and this is where cowboys like PC World make their grubby money.

There are no AGP 8x 3.0 cards that will work in anything less than a 4x 2.0 slot, and AFAIK they all require XP.

keithwalton · 09-07-2004, 01:05

erm some clarifications are in order me thinks.

Agp was a Pentium II thing. it was not in 486's nor pentium / mmx's. It was later introduced into the super socket 7 line for the amd k6/k6-II/k6-III line of cpu's.

Agp 3.0 is backwards complient with 2.0 but not 1.0. and 2.0 is backwards complient with 1.0 It's a voltage thing, agp 1.0 was 5v primary power, 2.0 is 3.3v and 3.0 is 1.5v there are 'humps' in cards / slots to stop you from plugging in incompatible devices.

Also the new PCI standard, PCI express, is not the same as PCI-X, the latter is a 64bit verson of pci and is parallel in terms of architecture. Express or PCI-E x16. Is new fangly and serial. Its twice as fast as agp in the cpu -> gpu direction, and 16x the speed in gpu -> cpu direction.
It is defined in terms of lanes. With x16 having 16 lanes. There is also x1 which is to replace pci 2.3 for less bandwidth hungry boards.

Chipsets have a limit to the number of lanes that they support. I believe the i915/925 chipset supports 20 lanes. which is used in 1 x16 slot and 4 x1 slots. I dont know how many lanes the e7225 (tumwater) chipset has for the xeon platform but it must be alot as it has 2 x16 slots (helpfull for nvidia sli) and several x1 slots.
The upcoming nforce 4 chipset has aledgidly 32 lanes which will also be dished out to support there sli technology. Rumour has it there will be an x8 slot for the second card.

As for graphics peformance, the first batch of pci-e cards are not any quicker clock for clock than there agp equivelents. (pci-e cards may be clocked slightly higher to give them a generic edge)
There is a reason for this, nvidia are using an on die bridge which translates pci-e to agp commands. Since the chip is natively an agp gpu it makes no use of the new features and is infact slower than a native agp card of the same spec in benchmarks sometimes it will equal perf when something else is the bottleneck (most of the time).

As for ati the r42x (420 being agp and 423 being pci-e) have a modular interface design.They are basically identical apart from one small part of the die which is the communcations protocol bit. The bulk of the chip communicates with this section which is either agp compliant or pci-e.

Neither 'solution' specifically demands or even makes use of the new features brought along with pci-e. This reminds me of the whole pci -> agp move several years back early agp cards were basically pci designed cards that sat on the agp bus. It took till the second generation (Agp 2x) cards before any real advantage was seen.

Unfortunutly direct comparisons are hard to make as pci-e boards carry other new features such as ddr2. So performance differences cant be singled out as there are severable variables.

I would though agree with the wait and see attitude. LGA775 is new and it'll take time for potential problems to become more apparent and be resolved (motherboard socket bit is fragile so far). Chips designed specifically for pci-e are on the way by the end of the year and should be a fair bit faster.

K

Answering other points, AGP 1.0 is 1x only. 2.0 covers 2x and 4x. 3.0 is 8x. Also 8x cards do support other os's than xp. 2000 for sure is suported and so is Me (whoever would willingly use that i dont know) 98 support is sketchy. Linux is also supported by nvidia cards :p

Richard M · 09-07-2004, 02:12

Quote:

Originally Posted by keithwalton

Unfortunutly direct comparisons are hard to make as pci-e boards carry other new features such as ddr2.

The new Radeon X800 AGP cards use DDR3.
I'm not going to bother waiting for PCI Express because it will be a good year or so until we'll actually need the bandwidth.

Bifta · 09-07-2004, 09:08

Quote:

Originally Posted by keithwalton

erm some clarifications are in order me thinks.

Agp was a Pentium II thing. it was not in 486's nor pentium / mmx's. It was later introduced into the super socket 7 line for the amd k6/k6-II/k6-III line of cpu's.

AGP also appeared on Pentium 1 boards, I had a Pentium 233 mmx years ago (not the P2 233) with an AGP port (which I used) on my motherboard.

keithwalton · 09-07-2004, 12:24

With regards to the ddr2 comment i was refering to system ram, not graphics as they are the same between boards.
Later era pentiums (mmx's) were socket 7. Intel shifter over to slot 1 at 233mhz with the p2, and brought some new features with it. The last intel chipsets for the p1 were the 430tx and vx. Neither of which had agp.
This however was at the time of amd's first big push in a long time with the K6 this chip rapmed to 266 (i think could of been 300 not sure) but in a dick dastidly move by intel socket 7 boards using there chipsets hit a ceiling. In comes Ali, SIS and via to save the day forming the super socket 7 format. Which brought the features of more modern slot 1 boards to the ageing s7 platfrom, as well as allowing for much greater speed. I believe the via mvp2 allowed upto 550mhz. Because the boards were pin compatible with s7. pentium chips worked just fine in the ss7's. Intel also quickly dried up supplys of there own boards yet kept there was a backlog of p1 chips to clear so pc manufacturers often used a p1 and ss7 combo.

K