i have a quick question

[myrick]

i have a friend whos helping me build a system hes tilling me that AGP is faster than pci e is this true ?

 

[Vile]

There's no way that's true lol

PCI Express is twice as fast (if not faster) than AGP. I used to have a chart with their speeds somewhere...

 

[Black_Solitare]

Put simply, no

PCI-E at full rate is roughly double that of AGP! With the lower end cards there wont be much of a difference between PCI-e and AGP but for higher cards a PCI-E is needed to push the higher texture rates.

If there is a PCI-E version of the card and you can afford it, then go for it! but remeber you need a PCI-E motherboard, which can be more money.

BS

 

[sleepdeprived82]

Are you sure he wasnt confusing AGP with PCI, in which case agp is a lot faster.

 

[cleeve]

The PCI-express bus is faster, but there is absolutely no performance difference between the AGP and PCI-express busses as far as videocard performance goes.

The newest videocards do not even saturate the AGP 8x bus yet.

An X800 XT AGP and X800 XT PCI-express will deliver exactly the same framerates.

 

[Vile]

Maybe, but sooner or later PCIx will be able to use the extra bus speed they have. Also, newest video card models come out in PCIx format and later AGP versions are available on SOME of the cards. PCIx also lets you use Crossfire and SLI.

 

[Black_Solitare]

And even though they havent been saturated the fact that there is more bandwidth will allow the card to push around data alot more effectivley.

The card will bottleneck slightly before it uses the full bandwidth, mainly because you never get all the bandwidth that you theoretically are allowed.

Im sure the X1800 or the 7800 GTX 512 pushes the bandwidth on the AGP (not that they will ever release them on AGP), especially with all the fancy stuff that the x1800 is supposed to allow you to do.

trying to push the x17 bus for SLI now, some american express rubbish. Seems a bit extreme if you ask me.

BS

 

[FlyGuy]

It doesn't really matter in the end which one is faster though. All the new mobos are PCIe as well as the new cards. So, in the end your choice is made for you

 

[cleeve]

Not all PCI-express boards allow you to use SLI or Xfire...
...and there is no data to support the supposition that an X1800 or 7800 would perform better on PCI-express than AGP.

If you're buying/building a new system, sure PCI-express is the way to go, for upgradability if for nothing else.

However, that's not what the poster asked.

Today, you get two identical GPUs with identical clockspeeds, and it makes no difference whatsoever if it's AGP or PCI-express...

If you have data that proves otherwise, please provide.

 

[Crashman]

i have a friend whos helping me build a system hes tilling me that AGP is faster than pci e is this true ?

Of course it's true, AGP has features such as fast writes that PCI-Express doesn't have. It's nearly always true that when you can find otherwise identical AGP and PCI-Express cards, the AGP card is around 1% faster on comparable boards.

In fact, this was such an embarrasing issue for nVidia that they specified the AGP cards be CLOCKED SLOWER to prevent them from outperforming the PCI-Express parts.

 

[Crashman]

There's no way that's true lol

PCI Express is twice as fast (if not faster) than AGP. I used to have a chart with their speeds somewhere...

Actually AGP is faster using today's card technology. We're not thinking about what will be available in two years yet.

 

[TabrisDarkPeace]

Firstly make sure "your friend" knows the difference between PCI and PCI Express (PCIe x16).

Some people also write PCIx (which is actually PCI-X and a totally different, non consumer video related slot - so read PCIx as PCIe in most cases).

PCI = 133 MB/sec shared by all slots (used by very old video cards, prior to AGP)

AGP 1X = 533 MB/sec (writes slower than reads).
AGP 8x = 4266 MB/sec (reads) and 533 - 4266 MB/sec (writes). - Minus any overheads.

PCIe x16 = 8533 MB/sec (reads and writes).

Of couse few cards actually come close to saturating the bus, and once data is written to video / texture memory reads are far more common than writes. (eg: Until the next level load, then write speed helps a little more).

PCIe x1 = 533 MB/sec. But isn't likely to be used for 3D video cards any time soon, the slot is too small to support 'long' video cards, and lacks bandwidth required for todays high end video cards aswell.

PCI-X = Mostly used for servers, high end RAID, multi-gigabit ethernet, etc. Very similar to PCI but cards chipsets are costly to manufacture compared to PCI Express (PCIe).

* If I've made any mistakes let me know, I'll correct them.

PCIe (PCI Express v16) does not require Side Band Addressing or Fast Writes, as it has equal speeds for reads and writes. PCIe x16 also has twice the peak throughput of AGP 8x.

Fast Writes was an addition to AGP for this very reason as originally AGP write performance was only a fraction of its read performance. PCIe x16 does not require the AGP feature set as it is technically superior now, and AGP has already been phased out of consumer mainboard chipset manufacturing.

Also bear in mind that mainboards with PCIe x16 slots are going to have better features and support current (and future) generation CPUs, eg: AMD Athlon64, 64 X2, 64FX, Intel Pentium 4 600 series, and Pentium D 800 & 900 series, etc.

Also other new features such as Serial ATA (SATA), with NCQ (Native Command Queing) Hard Disk Drives, Decent integrated Gigabit Ethernet (for 1000 Mbps LAN), and fairly good integrated audio (Hardware accelerated, SPDIF, 5.1 - 7.1), etc are typically paired with PCI Express x16 mainboards to boost 'overall' performance.

AGP 8x (x goes after not before like in PCIe x16) is acceptable for 2nd hand PCs and low end 'Sempron' or 'Celeron' PCs. But you can get PCIe x16 mainboards for under AU$100 so why anyone would get an AGP 8x mainboard nowadays is totally beyond me.

For example check the price of the: http://www.foxconnchannel.com/products_motherboard_2.cfm?pName=6150K8MA-8EKRS ; to get a rough idea. It's dirt cheap, and has integrated nVidia GeForce 6150 to boot.

Large image to help you see the differances: http://www.foxconnchannel.com/picBig.cfm?picName=m_6150K8MA-8EKRS.jpg

Just add a (Socket 939) CPU, eg: AMD Athlon64 3200, and 2 x 512 MB (or 2 x 1024 MB) PC3200 DDR-SDRAM, install in a case w/ 350+ Watt PSU = Instant PC pretty much.

For a cost effective video card upgrade (GeForce 6150 is slow, but 'acceptable' to some.... these cards are many times more powerful) consider a nVidia GeForce 6600 GT, 6800 GT or 6800 GS, or ATI Radeon X800 GTO or X800 XL.

It also includes a PCIe x16 slot which can permits upgrading to a very high end ATI Radeon X1800 XT or nVidia 7800 GTX-512 ($1000+ as of Jan 2006) video cards. (....and will support newer PCIe x16 video cards that AGP will never be able to provide power to. PCIe x16 specs up to 75 watts for video card alone, a marked improvment over AGP 8x).... thus in 12 - 18 months time even faster PCIe x16 video cards will be available that will never be offered in AGP varients.

I think someone is pulling your leg, or trying to rip you off, or persuade you to buy old hardware at an inflated price.

Hopefully that'll cover you, or at least encourage you or "your friend" to dig a little deeper into the hardware world of PCs.

Plenty of people on TomsHardware Forums willing to help a stranger in need.

 

[Crashman]

I figured someone was making an argument for the sake of argument. And that argument is right, two GeForce 6600GTs, one PCI-Express and the other AGP, will hand the win to the AGP version when you increase the clock speeds to that of the PCIe version. Yes, I'm being completely straight, nVidia handicapped the AGP version to make it slower than the PCIe version, because at equal clock rates, the AGP performed better.

Same thing can be found with the 6800GT.

 

[TabrisDarkPeace]

True, but assuming he isn't overclocking, or being sold overclocked equipement (illegal anyway, but with a BIOS flash pre-sale it could happen) then the PCIe x16 video cards (which are clocked higher usually anyway) would be the best way to go performance wise.

They'll also have a higher resale value 18-24+ months down the track than the AGP varients, since no-one will want to buy 2nd hand AGP cards in that time.

Unless he's getting a very good deal on the (2nd hand ?) AGP gear, and sounds like he's concerned that he isn't getting a good deal. Wouldn't he be better off going for the 'current' technology (for the above 2 reasons) right ?

 

[Crashman]

I don't think this question was leading to a purchase, it was probably a conversation where some guy said "PCI-Express is faster" and another guy said "No it's not" and then found a way to prove that today's PCI-Express graphics cards don't perform as well as their AGP counterparts when everything else is equal.

The difference is small, but large enough to make a "just for arguments sake" argument.

 

[TheGreatGrapeApe]

True, but assuming he isn't overclocking, or being sold overclocked equipement (illegal anyway, but with a BIOS flash pre-sale it could happen)

How is that illegal?

What law did BFG and eVGA break by selling OC'ed cards? I don't know of any law that would exist that would be punitive t someone providing more than exptected. There are consumer protection measure for being sold less than advertised, but even then usually more hassle than it's worth.

 

[Crashman]

I think he's talking about fraudulent overclocking, you know, like wusy does, selling an unlocked/overclocked 9800SE as a 9800 Pro without disclosing the modifications.

 

[cleeve]

I think he's talking about fraudulent overclocking, you know, like wusy does...

lol.

Crash is right as well, the noobs have turned this into a "Buy PCI-express over AGP" debate, but the original poster never mentioned buying anything.

He asked if AGP was faster than PCI-express and, for all practical purposes, it is not.

Two identical cards and clockspeeds perform the same way on either interface. (maybe even a slight nod to AGP from what Crash is saying, interesting)

If you're buying new, you'd be crazy not to buy PCI-express of course. but that's not what was asked.

 

[TheGreatGrapeApe]

I think he's talking about fraudulent overclocking, you know, like wusy does, selling an unlocked/overclocked 9800SE as a 9800 Pro without disclosing the modifications.

Yeah, that I understand, or the selling of those 'fake' AMDs and OCing OEM box and selling them as XP2600+ instead of 2400+. But OC'ing a GF6800GS AGP to PCIe level and selling it as such, is OK. OF course the illegal usually involves some things like sending it through the mail, because consumer protection laws are just so weak.

Funny you rememebr Wusy's sale, I dot to, and I remember the uproar it caused us. Just another example of buyer beware, get informed of course.

 

[FlyGuy]

Crash is right as well, the noobs have turned this into a "Buy PCI-express over AGP" debate, but the original poster never mentioned buying anything.

He asked if AGP was faster than PCI-express and, for all practical purposes, it is not.

Two identical cards and clockspeeds perform the same way on either interface. (maybe even a slight nod to AGP from what Crash is saying, interesting)

If you're buying new, you'd be crazy not to buy PCI-express of course. but that's not what was asked.

Good point! Damn noobs....oh wait...uh...we all have to start somewhere!

 

[Black_Solitare]

I think you'l find they were buying things being that it was mentioned that

helping me build a system

Does this not imply the fact that there is indeed money being spent?

The fact that we have explained the differences will now allow him to make an informed choice.

And have fun with it!

BS

 

[cleeve]

Good point! Damn noobs....oh wait...uh...we all have to start somewhere!

BACK, NOOB! Back I say!

Into the abyss with you!

Yes, there is nothing wrong with being a noob. But don't expect to be corrected by us old hoss' without getting razzed a bit.

At least until you've built up some street creds.

 

[nottheking]

Well, for some the abovementioned features, AGP 8x does, on a level field, currently out-perform PCI-express x16, even though it has roughly double the bandwidth of AGP 8x. Of course, also keep in mind some of the other changes as well. Also, for the love of (insert holy name here) please remember to know the difference between PCI, PCI-e, and PCI-x. For things like this, it's a point where I say that Wikipedia is your friend. (AGP, PCI, and PCI-express)

 

[Whizzard9992]

I'll give you the short answers:

Is PCIe faster than AGP? Yes.

Will you see a difference between an AGP card and a PCIe card of the same model? Probably not.

AGP was designed to allow the bandwidth-hungy graphics card to run on a different bus than the peripherals. It was also designed to use system memory instead of on-board memory if it ever ran short (For textures and such). This was really a pipe dream, for the most part, because of the latency involved in accessing system RAM versus on-board RAM. Someone can correct me of I'm wrong, but I'm pretty sure that it's up to the software (game, w/e) to handle defining how memory is marshalled on the vid card, and with computers having different AGP memory apertures, most programmers don't even utilize this feature.

The graphics bus is used to pass instructions and initially load textures into on-board memory, neither of which should ever choke an 8x bus. A good example is that SLI setups usually run 8x PCIe on each slot, which is essentially the same speed as AGP anyway.

Why did they replace AGP with PCIe? There are a lot of articles why, but the short is that PCIe is assymmetric with dedicated bandwidth per channel, and it doesn't need to be a seperate bus from the peripherals, meaning less heat, less cost, and fewer transistors per IO bridge (in theory).

Depending on the chipset, PCIe may give you better performance anyway just based on the fact that it revamps the IO architecture of the board, but as for a PCIe card being faster than an AGP card? Nope.

 

[Whizzard9992]

P.S. AGP WILL be phased out, and you likely won't find many high-end cards running AGP. If you want your computer to be future-proof, go PCIe.

I figured someone was making an argument for the sake of argument. And that argument is right, two GeForce 6600GTs, one PCI-Express and the other AGP, will hand the win to the AGP version when you increase the clock speeds to that of the PCIe version. Yes, I'm being completely straight, nVidia handicapped the AGP version to make it slower than the PCIe version, because at equal clock rates, the AGP performed better.

Same thing can be found with the 6800GT.

?? That's interesting. Can you back that up? I'm curous.