PCI Express is worthless [Archive]

sappo

03-11-04, 03:31 AM

PCI express is worthless which is basically what tomshardware says here (http://www.tomshardware.com/graphic/20040310/index.html). It's about time someone pointed out the fact that there is virtually no visible difference between agp 8x and 4x and that the same may apply to PCI express. I was beginning to think I was the only person in the world who thought the 4gb/s the pci express offered was worthless when you have a top end video card with a bandwidth of over 20gb/s.

FarEast

03-11-04, 04:06 AM

Ok I think the whole point of that review was to get advertising revenue from XGI who happen to be one of the for runners in PCI express which out of 14 pages had an advert on 8 of them advertising PCI Express. Funny that? Why would any company want to advertise on a site that is slating a product they specailise in? odd Isn't it?

Not really as the saying goes " There is no such thing as bad publicity!"

And a reveiw that is controversial slating something that is actually going to increase the speeds computer components comunicate at is going to get read. Thus creating awareness of a company "XGI" that is dwafed by ATI and Nvidia.

PCI Express isn't just for the GPU to use but other hardware as well... like Giga-ethernet.

PCI Express is the future of PC's and hardware interface... what Tom's Hardware doesn't explain is that the whole layout and make up of your motherboard will be different thus utilising the PCI X more. You might want to have a look on other sites that don't bend facts or use a different slant on the subject to create traffic to make advertising revenue.....

Sorry Sappo but you got sucked in.

But hey on a brighter note ... might be in your neck of the woods soon!

juliendogg

03-11-04, 06:25 AM

I don't even take the time to read anything at Tom's anymore. Pretty pointless IMO. :D. Fact is, none of us end users will really know what PCI express can do till we see it properly implemented.

J.

L337 M33P

03-11-04, 06:41 AM

PCI-express won't do much for graphics cards certainly, but in the mass-storage controller area (Think ordinary PCI devices) RAIDed arrays of hard drives will no longer be limited by 133MB/s. I read somewhere that PCI 1x slot is like 2.5Gb/s or something. Still, not a good enough reason to upgrade :-/

JigPu

03-11-04, 10:09 AM

PCI-Express is far from worthless :) It may be a bit ahead of it's time, but it's like saying SATA is worthless since HDs can't max out ATA-133 on their own (and that you can buy rounded cables if you want better airflow).

Few things in the computer industry are worthless. They might give no improvement right now, and mabey not for a while to come. But you'd be much happier to have a standard set in place which can handle the higher speeds two years back instead of scambling to make one when you're hitting the performance celing.

If PCI-Exress was targeted to replace AGP only, THEN I'd say it's almost worthless since we aren't using AGP 2x even :D But it's going to replace the PCI architecture as a whole AFAIK.

Benifits of PCI-Express over PCI:
1) Each (1x) device has it's own independant bandwith of 266MB/sec. Currently, PCI shares a total bandwidth of 133MB/sec between all devices (AGP not included). This means your HD, NIC, soundcard, tv cards, etc. are all competing for a limited amount of bandwidth.

2) Scalable bandwidth. If a device in the future needs more bandwith than 266MB/sec all to itself, adding a second line will double the bandwith (creating a PCI-Express 2x slot). The SATA controller could be connected to the northbridge via a PCI-Exress 1x connection (limiting each drive to 266MB/sec). High end RAID controllers could use 2x connection (giving the RAID a maximum of 533MB/sec).

3) Easier to manufacture. Since PCI-Express is (AFAIK) serial based, it means mobo manufactures don't have to design such complex boards with as many traces. This makes it cheaper for them to manufactuer.

Everybody seems to think PCI-Exress is out to soley replace AGP. Just look at the name! :) Yes, it's targeted to graphics cards first but in probably a year or two we'll be seeing other devices using the interface.

JigPu

wpmegee

03-11-04, 10:45 AM

I lost 2000 3d marks (01) on my 9700 when I switched off 8x agp. I've only got 128mb of vram, tho, so i think the bus bandwidth comes into play more when the ram on the card gets saturated.

violineb

03-11-04, 01:49 PM

Like JigPu said, PCI E isn't meant solely as a replacemen for AGP. The 133mb/sec bottleneck of PCI is something that has long been overdue for replacement IMO. I'm glad something is finally being done. As for the ton of XGI ads in that article. Uh, no comment. If only something like the Voodoo 5500 could be practical again :(

Evnas

03-11-04, 02:28 PM

Originally posted by wpmegee
I lost 2000 3d marks (01) on my 9700 when I switched off 8x agp. I've only got 128mb of vram, tho, so i think the bus bandwidth comes into play more when the ram on the card gets saturated.

Infact, thats the only time it really comes into play ;) When people say "We arent taking advantage of 8x AGP yet", what they dont realize is the only time the bandwidth is used is A) when loading textures (aka, loading time) and B) when the card gets full (which doesnt happen very often even with 128mb cards), and your system ram needs to be used instead. No matter the interface, however, be it AGP or PCI-Express 16x, there will be a large performance hit when the system ram needs to be used because your going from bandwidth in the 30GB's and 40GB's, to 2GB (AGP8x) or 4 (PCI-Express, or whatever PCI-Express 16x bandwidth is) when the system ram needs to be used.

Overclocker550

03-11-04, 04:38 PM

somethings wrong if you lose 2k from switching agp down from 8x :/ anyway pci-e isnt just to replace agp, its to provide more bandwith to other stuff and free cpu cycles

FarEast

03-11-04, 05:30 PM

Originally posted by JigPu
PCI-Express is far from worthless :) It may be a bit ahead of it's time, but it's like saying SATA is worthless since HDs can't max out ATA-133 on their own (and that you can buy rounded cables if you want better airflow).

Few things in the computer industry are worthless. They might give no improvement right now, and mabey not for a while to come. But you'd be much happier to have a standard set in place which can handle the higher speeds two years back instead of scambling to make one when you're hitting the performance celing.

If PCI-Exress was targeted to replace AGP only, THEN I'd say it's almost worthless since we aren't using AGP 2x even :D But it's going to replace the PCI architecture as a whole AFAIK.

Benifits of PCI-Express over PCI:
1) Each (1x) device has it's own independant bandwith of 266MB/sec. Currently, PCI shares a total bandwidth of 133MB/sec between all devices (AGP not included). This means your HD, NIC, soundcard, tv cards, etc. are all competing for a limited amount of bandwidth.

2) Scalable bandwidth. If a device in the future needs more bandwith than 266MB/sec all to itself, adding a second line will double the bandwith (creating a PCI-Express 2x slot). The SATA controller could be connected to the northbridge via a PCI-Exress 1x connection (limiting each drive to 266MB/sec). High end RAID controllers could use 2x connection (giving the RAID a maximum of 533MB/sec).

3) Easier to manufacture. Since PCI-Express is (AFAIK) serial based, it means mobo manufactures don't have to design such complex boards with as many traces. This makes it cheaper for them to manufactuer.

Everybody seems to think PCI-Exress is out to soley replace AGP. Just look at the name! :) Yes, it's targeted to graphics cards first but in probably a year or two we'll be seeing other devices using the interface.

JigPu

Great post!

sappo

03-11-04, 08:59 PM

Originally posted by JigPu

Everybody seems to think PCI-Exress is out to soley replace AGP. Just look at the name! :) Yes, it's targeted to graphics cards first but in probably a year or two we'll be seeing other devices using the interface.
JigPu

I dont think the fastest hard drives are fast enough to create a bottleneck in the PCI interface. The same definitely holds true for your NIC, soundcard, and tv tuners. Some things flat out don't need more bandwidth. Furthermore, there's no product on the horizon that makes me think I'll need that extra bandwidth. Maybe flash memory? And perhaps rigs with integrated video that rely solely on your main ram.

Nevermind Tom puts it better:
The same holds true for video upstreams - the system memory will be hard-pressed to keep up. Even the newest hard disks can only write an average of 50MB/s, a data rate that even PCI writes could handle with ease. And as far as real-time video editing is concerned - the CPU will still need to make a few calculations every now and then - and again the memory will probably prove to be the bottleneck. Continuous data transfers at 4GB/s look set to remain a fantasy for a while to come.

Evnas

03-11-04, 09:18 PM

Originally posted by sappo

I dont think the fastest hard drives are fast enough to create a bottleneck in the PCI interface. The same definitely holds true for your NIC, soundcard, and tv tuners.

Try moving tons of files over a 100mbit network and at the same time trying to record something with a TV tuner...i can tell ya right now its not fun, nor "fast enough"

Mico

03-11-04, 10:43 PM

64-bit PCI has been in servers for a long time? Why? Because of the bandwidth for RAID arrays. It's not useless, otherwise, people wouldn't use it.

JCLW

03-11-04, 10:50 PM

I feel like I post this once a week: The move to PCI-E graphics is not only for bandwidth reasons.

Dany Lepage, Splinter Cell - X Lead Programmer @ Beyond3D (http://www.beyond3d.com/forum/viewtopic.php?t=9986)

In my opinion, PCI-E will have a major impact on how games are designed because you should be able to finally read from the graphic chip memory without breaking the streaming of the transactions between the core logic and the GPU. PCI-E is a point to point bus meaning that it works just like HyperTransport (dedicated upstream/downstream). On AGP, when you switch between read and write, you have to turn around and that takes time.

This should allow a new range of algorithms to be possible (like on consoles). You could use the GPU to calculate very quickly zone of dangers when the player is throwing a grenade (physic blast shadowing). The information could then by passed to your AI and Physics engine to help the AI makes a good decision on how to react to this event and to find out which objects should be impacted (where and how) by the blast. This kind of shadowing algorithm may or may not be efficient (compared to distributed ray casting) but it gives some ideas.

So overall, PCI-E won't have direct impact on rendering but it will have a big impact on engine design (only programmers will notice but games are going to get better more quickly).

All of this can be done on the CPU but people are going to start looking at the GPU to do other things than just graphics. All of this because of PCI-E.

micamica1217

03-11-04, 10:53 PM

snyper1982

03-12-04, 12:47 AM

Originally posted by sappo

I dont think the fastest hard drives are fast enough to create a bottleneck in the PCI interface. The same definitely holds true for your NIC, soundcard, and tv tuners. Some things flat out don't need more bandwidth. Furthermore, there's no product on the horizon that makes me think I'll need that extra bandwidth. Maybe flash memory? And perhaps rigs with integrated video that rely solely on your main ram.

Nevermind Tom puts it better:

lol.

sappo

03-12-04, 01:56 AM

Originally posted by Evnas

Try moving tons of files over a 100mbit network and at the same time trying to record something with a TV tuner...i can tell ya right now its not fun, nor "fast enough"

If you're encoding at DVD quality in mpeg2 format, that's around 1MB/sec. A 100mbit network has a absolute MAX limit of 12MB/sec. That's nowhere near the limit of PCI.

Sounds like you've got a TV tuner that cannot encode mpeg2 on the fly. In that case you need a lot more bandwidth but your PCI still isnt the bottleneck, your hard drive is. PCI-E is not the answer. A quality tuner is.

Good grief. Firewire and USB2 provide ~20MB/sec transfer rate. That's more than enough to transfer hi resolution video on the fly.

PreservedSwine

03-12-04, 08:03 AM

Originally posted by JCLW
I feel like I post this once a week: The move to PCI-E graphics is not only for bandwidth reasons.

Dany Lepage, Splinter Cell - X Lead Programmer @ Beyond3D (http://www.beyond3d.com/forum/viewtopic.php?t=9986)

This needs a bump....:D

snyper1982

03-12-04, 10:11 AM

JigPu

03-12-04, 10:31 AM

Originally posted by sappo
If you're encoding at DVD quality in mpeg2 format, that's around 1MB/sec. A 100mbit network has a absolute MAX limit of 12MB/sec. That's nowhere near the limit of PCI.

Sounds like you've got a TV tuner that cannot encode mpeg2 on the fly. In that case you need a lot more bandwidth but your PCI still isnt the bottleneck, your hard drive is. PCI-E is not the answer. A quality tuner is.
I'd LOVE a tuner that encodes MPEG2 on the fly, but alas they are FAR more exensive than a run of the mill tuner.

If you're catpuring raw (which I'd be doing since I can't afford good tuner and don't feel like sacrificing quality by having the CPU encode on the fly), the tuner should take 27MB/sec for video (640x480 * 24bpp *30fps / 8 / 1024^2). An additional 1MB/sec for raw WAV data can be expected.

So, that's 28MB/sec to the northbridge. Then another 28MB/sec from the northbride to the HD (remember that PCI devices CANNOT talk directly to each other). Total bandwith used so far: 56MB/sec

The NIC will obviously be the bottleneck for the HD, so let's see where that gets us. We can assume 80% useage of the NIC if the other system is pretty fast. 80Mb/sec turns into 8MB/sec. So, 8MB/sec northbridge to NIC and 8MB/sec HD to northbridge. Total bandwith used so far: 72MB/sec

There you go :) Now you have math to prove that you don't need PCI-Express for bandwidth. Now, should I do some more math showing that we don't need SATA for bandwith either?? Bandwith is not the only reason PCI-Express is better than PCI, just like why bandwith is not the only reason SATA is suppierior to ATA.

JigPu

sappo

03-12-04, 09:52 PM

The best on the fly codec for raw video I've used is indeo with "fast compress" checked. I havent used in it a while but there is literally NO noticable difference between that and uncompressed avi. Best of all it uses VERY little processor power. I cant remember, but I think it compresses raw video by half or more.

Ok, so maybe PCI-E isn't just for higher bandwidth but to "change the way games are made". Pardon me for being a skeptic, but I've heard how lots of things are going to "change the future of video games" but few, if any, have actually delivered as promosed (MMX and AGP 1X, 2X, 4X, 8x to name a few). In addition, the explanation as to why PCI-E is going to be so great are pretty shakey IMO.

Another huge hurdle that PCI-E needs to overcome is that it must be mass produced before it becomes cheaper. The general public wont be very willing to spend a lot more for PCI-E if 1) it's not noticably faster than PCI and 2) If it doesnt offer a competitive price tag compared to PCI. All these promises about PCI-E being the "future" will fall flat IMO

JCLW

03-12-04, 11:52 PM

If Dell only sells the general public PCI-E computers, then the general public will buy PCI-E computers. And Dell has commited to going 100% PCI-E by the end of the year. It's cheaper for them. And good marketing ammunition.

PCI-E is faster, cheaper, and easier. The only downside is that it is different (if you can even count that as a negative).

Why wouldn't you want PCI-E?

captain_sHiFTy

03-13-04, 12:36 AM

"Why wouldn't you want PCI-E?"

because we would have to buy a new motherboard and possibly new devices to support it. i dont wanna pay for a new sound card/video card just so i can run something thats arguably better, but wont be utilized for a few more years. you forget that the average lifespan for a computer is only a few years.

its never a good idea to invest money in a product with brand new technology. it takes time to iron out all the wrinkles. by the time its utilized fully a better version will be out, or a whole ton of new technological advances that will support the increase in bandwidth. i dont have the technical expertise to speculate on what these might be, but i do know it's going to happen. thats the way the industry works.

of course PCI-Express is going to be BETTER. of course its going to be used. of course if you're buying a new motherboard you should wait the little while for pci express so you can take advantage of new devices as they come out.

but its not the be all and end all of advances. its like the invention of the wheel without the invention of the wagon. whats the point of having something that'll roll if you dont have anything to roll with it? all you have is a wheel to show off to all your friends. you need to wait for the wagon to be invented to use your new toys, so why buy now when you can buy later and get a fully utilized pci express along with all the other new advances and gadgets being invented for motherboards.

TUK101

03-13-04, 01:29 AM

I love how people get so negetive about upcoming improvements to the very thing that they are typing the message on. Faster and more efficient? Who doesnt want that? Now if only the same could be said for the thing that I drive to work........ :rolleyes: . Geez, I remember the same debate a few years back when they where making the jump to AGP slots becoming the norm. People where saying that why do that when we arent even taking full advantage of the bandwidth that a PCI slot can provide. Well I think that we can all appreciate what the AGP slot has done for our games and movies and graphics as a whole. Just because we arent fully using what is available to us now, dont you think that the R&D guys at Abit and MSI etc. have seen where the true bottlenecks of a computer is and are trying thier best to fix it before "we" the public start ranting about it. If they really figured that we dont need all that power then we would still be running on 256 color ISA slot video cards. ;)

JCLW

03-13-04, 02:03 AM

I'm sure you'll still be able to get AGP video cards and PCI soundcards years from now. How long has AGP been around? And yet you can still buy PCI video cards. And if you look around it's not that hard to find ISA soundcards, modems, or NICs.

Besides, there will be transition boards with both PCI-E and regular PCI buses for those not wanting to replace everything at once, just like there were boards with both ISA and PCI slots. In fact my P2B-D workstation board has two ISA slots on it.

Anyways...

Maybe it's just me but I think it's funny how much people dislike change.

Happy weekend everyone! :beer:

sappo

03-13-04, 07:02 AM

Originally posted by JCLW
Anyways...

Maybe it's just me but I think it's funny how much people dislike change.

It's not change that's bad. It's when companies try to rally around products that are supposed to be so awesome but they wind up being much more expensive and have no real improvements *cough RDram cough* If PCI-E was backwards compadible that would be a lot easier to swallow. I dont even want to think about how much more expensive my PCI modem will be on PCI-E. Plus, I highly doubt I'll see much of a performance increase when you're downloading at 56K.

harryinny3

03-13-04, 07:19 AM

That we are going to need a new case and power supply also because of the BTX form factor thats going to be used.

Harry

Mico

03-13-04, 12:12 PM

I'm pretty sure that PCI-X won't require a BTX board though. AMD will want a hand in this, and I'm pretty sure they'll get one.

JCLW

03-13-04, 12:44 PM

I'm not sure we'll ever see PCI-X on a BTX board. ServerWorks (Broadcom) seems to be the only company who is still going to make PCI-X chipsets, and most of their stuff ends up in rack mount.

harryinny3

03-13-04, 12:47 PM

website you will find somewhere where the say that All intel boards are going to Start being BTX boards by years end or so.

Harry

capmuffin

03-13-04, 12:49 PM

well i was told by a guy at nvidia when i called up that it was marketing (i know the guy personaly) ? true?

snyper1982

03-17-04, 10:20 AM

from what i understand pci-e IS backwards compatible, the first gen. mobos will have 1 x16, 2-3 x1 or x2, and 2 or 3 legacy pci slots, i remember reading that somewhere, the only real downside to pci-e is the video part. i swear, you people want faster and better well, here it is, the faster and better parts have to have a foundation, and pci-e exactly that. one of them has to come first, and no nic or video card manu. is going to produce products for a connection method that is not availible. so get over it, pci-e WILL BE the new standard, whether you want it to or not.

Overclocker550

03-17-04, 01:18 PM

I got nothing against pci-e as long as agp countinues to be supported for years to come :)

JCLW

03-17-04, 01:27 PM

Originally posted by snyper1982
from what i understand pci-e IS backwards compatible

I believe it's backwards compatible only in that a motherboard manufacturer can get a PCI-E <-> PCI bridge to add three or four PCI slots. You could also add a PCI-E <-> AGP bridge to a motherboard in order to get an AGP slot if you want. Even ISA slots would be possible if someone threw together a PCI-E <-> ISA bridge.

Aslan

03-17-04, 01:45 PM

Yep, I also heard that someone is coming up with a AGP -> PCI-E bridge slot so you can stick your AGP video card in a PCI-E slot.

As for actually having an AGP slot with PCI-E, I heard that only SiS is attempting to do this, but they were having difficulties with it the last I checked.

Originally posted by snyper1982
i swear, you people want faster and better well, here it is, the faster and better parts have to have a foundation, and pci-e exactly that. one of them has to come first, and no nic or video card manu. is going to produce products for a connection method that is not availible. so get over it, pci-e WILL BE the new standard, whether you want it to or not.

Exactly. Building the foundation is the part some people tend to ignore. Usually the first iteration (AGP, SATA, etc) fails to outperform the previous standard so then a bunch of reviewers immediately declare it a failure without allowing manufacturers to fully adapt and develop new technology for the new foundation (incidentally, just like what Tom did with that article, done even before PCI-E has even come out) :rolleyes:

JCLW

03-17-04, 01:55 PM

The nV PCI-E bridge works both ways - maybe someone will buy some to put on a motherboard.

You could have some silly setups then, ie: Chipset <-> PCI-E bus <-> PCI-E to AGP bridge <-> AGP bus <-> AGP to PCI-E bridge <-> Video card.

snyper1982

03-17-04, 03:49 PM

the bridge is not a slot where you stick your card, it is intergrated into the motherboard to allow an agp slot to comunicate with the pci-e bus. it doesnt matter how its backwards compatible, it will still offer legacy pci slots for pci cards, for at least 1-2 most likely more generations of mobos. i expect to see at least 1 standard pci slot in mobos for at least the next 3 years. look how long isa hung around with only one slot after pci took over.