AGP vs. PCIe -- relative value

[andrew.gullans]

I remember when 8x AGP was all the rage. I've got a 128MB GeForce4
MX440 8xAGP card w/TV-out, and I'm planning on building a 3200+
Venice-powered GA-K8U-939 with 2x1024 Patriot DDR400 (cost of
MB+CPU+RAM=$321.ish) to take advantage of it. (I'm looking into Eve
Online and some other MMPOGs).

At the same time, the A8R-MVP low-cost SLI board looks real nice, but I
don't know if I feel the need to fork over $xxx on a PCI-express x16
ATI card (the A8R runs ATI's Crossfire northbridge + Uli(?) southbridge
providing actual SATA2, gigEth, etc,etc,etc). Besides, the A8R only
allows 16x with a single PCIe video card; if you instal two, they both
drop to 8x.

Which do you think I should go with, and more than that, what are your
thoughts of how these LAST generation AGP cards fare against these
FIRST generation PCIe cards; how much of an improvement are you really
seeing with the technology at this stage, and how much improvement do
you expect to see as the dual x16 express solutions mature in the next
few chipset and hardware revisions?

 

[First of One]

I remember when 8x AGP was all the rage.

8x AGP received a lot of publicity and marketing dollars. Its performance
benefit over AGP4x/2x is non-existent in real-world games. See:
http://www.sudhian.com/showdocs.cfm?aid=554

I've got a 128MB GeForce4
MX440 8xAGP card w/TV-out, and I'm planning on building a 3200+
Venice-powered GA-K8U-939 with 2x1024 Patriot DDR400 (cost of
MB+CPU+RAM=$321.ish) to take advantage of it. (I'm looking into Eve
Online and some other MMPOGs).

You have a MX440 and actually plan to build a system *around* it to play
games? The MX440 is a cheap, low-end card, four generations old, based on
Geforce2 MX technology, circa 1999. The MX440 would be an enormous
bottleneck in the system you are planning.

At the same time, the A8R-MVP low-cost SLI board looks real nice, but I
don't know if I feel the need to fork over $xxx on a PCI-express x16
ATI card (the A8R runs ATI's Crossfire northbridge + Uli(?) southbridge
providing actual SATA2, gigEth, etc,etc,etc). Besides, the A8R only
allows 16x with a single PCIe video card; if you instal two, they both
drop to 8x.

Yes, and PCIe x8 is overkill for any video card today. NVidia NF4 SLI x16
motherboards, with 16 lanes to each video card, perform no better than the
old NF4 SLI boards, which split the lanes to 2x8. For the same reasons, all
else being equal, expect *zero* performance gains from RD580 over the RD480
chipset.

The primary reason for RD580's existence is having an *ATi-branded*
southbridge that supports SATA2, GigE, full-speed USB 2.0, etc. The consumer
shouldn't care whose logo goes on the chipset as long as it works. The
existing RD480 + ULi solution works just fine.

The primary reason to upgrade to a PCIe motherboard now is to be able to use
the latest generation video cards, as they are no longer offered in AGP
form. That, or if you want to build a low-cost RAID5 server and stick a RAID
controller card in the PCIe slot.

 

[J. Clarke]

I remember when 8x AGP was all the rage. I've got a 128MB GeForce4
MX440 8xAGP card w/TV-out, and I'm planning on building a 3200+
Venice-powered GA-K8U-939 with 2x1024 Patriot DDR400 (cost of
MB+CPU+RAM=$321.ish) to take advantage of it. (I'm looking into Eve
Online and some other MMPOGs).

At the same time, the A8R-MVP low-cost SLI board looks real nice, but I
don't know if I feel the need to fork over $xxx on a PCI-express x16
ATI card (the A8R runs ATI's Crossfire northbridge + Uli(?) southbridge
providing actual SATA2, gigEth, etc,etc,etc). Besides, the A8R only
allows 16x with a single PCIe video card; if you instal two, they both
drop to 8x.

Which do you think I should go with, and more than that, what are your
thoughts of how these LAST generation AGP cards fare against these
FIRST generation PCIe cards; how much of an improvement are you really
seeing with the technology at this stage, and how much improvement do
you expect to see as the dual x16 express solutions mature in the next
few chipset and hardware revisions?

Well, an MX440 is not a "LAST generation AGP card", it's a "three
generations old low end crap AGP card". If it was a Ti it would be another
story--it would still be three generations old but at least it would have
had decent performance when it was new.

Crossfire is not SLI, SLI is not Crossfire, they are competing technologies,
one from ATI and the other from nvidia--if you want to use dual ATI boards
go with Crossfire, if you want to go with dual nvidia go with SLI.

The speed of the slot isn't really of any great importance--AGP 4x, AGP 8x,
PCI Express x8, and PCI Express x16 all give pretty much the same
real-world video performance.

If you are doing any kind of current-generation gaming then you need a board
with DirectX 9 acceleration and reasonable performance, and your MX440 has
neither.

 

[dave]

In the other two replies both say that tthe speed of the slot is
not that important for current games - that is true but it's
quite likely that future games will make more use of the
extra speed, especially as the amount/size of the graphics
included in games is likely to increase exponentially as
they approach true realism.

Note that the speed of the slot probably does have an
affect now in many games but it usually just means a
somewhat quicker transfer from one level/section of
a game to another rather than a speedup in active action.

 

[First of One]

In the other two replies both say that tthe speed of the slot is
not that important for current games - that is true but it's
quite likely that future games will make more use of the
extra speed, especially as the amount/size of the graphics
included in games is likely to increase exponentially as
they approach true realism.

The speed of dual-channel DDR400 is 6.4 GB/s. PCIe x8's bandwidth already
exceeds that. PCIe x16 won't speed up the loading of textures from system
memory because it's not the bottleneck.

Note that the speed of the slot probably does have an
affect now in many games but it usually just means a
somewhat quicker transfer from one level/section of
a game to another rather than a speedup in active action.

I once thought about that, too. Then someone did a quick calculation to see
how long it takes to fill up 512 MB of video memory through the AGP 8x bus.
It takes about 0.12 sec with AGP 8x. Even if PCIe can double the transfer
speed, the time saved would be 0.06 sec. Blinking your eyes takes longer.


The only times dual x16 slots may be useful are:
1. X1600 Crossfire without a dongle. (Though the economic value of such a
setup versus a single X1900 is questionable.)
2. A PCIe x4 or x8 RAID card needs one of the slots. This is actually a
legitimate reason, since the second full-length PCIe slot on RD480 boards
probably can't function with a single video card installed (the video card
will want all 16 lanes).

 

[JT]

I remember when 8x AGP was all the rage. I've got a 128MB GeForce4
MX440 8xAGP card w/TV-out, and I'm planning on building a 3200+
Venice-powered GA-K8U-939 with 2x1024 Patriot DDR400 (cost of
MB+CPU+RAM=$321.ish) to take advantage of it.

Uh, no current rig is going to take advantage of that video card unless
you're planning on playing nothing but 3 year old games and older. The MX400
cards were decent budget cards, but only average performers even when they
first came out.

 

[TonyC]

I remember when 8x AGP was all the rage. I've got a 128MB GeForce4

MX440 8xAGP card w/TV-out, and I'm planning on building a 3200+
Venice-powered GA-K8U-939 with 2x1024 Patriot DDR400 (cost of
MB+CPU+RAM=$321.ish) to take advantage of it.

Are you completely nuts mister!?!?! You're building a new PC to take
advantage of a videocard that was utter shite when it was first released
never mind comparing it with current cards. It must've cost all of £40 way
back when. First thing you need to do, and urgently, is realise your
videocard is total crap and unsuitable for gaming.

TonyC.

 

[DCT]

Im no tech expert, but I have read that the 1st Gen PCI-E cards are about 4X
faster than AGP X8...depends on other variables tho...mobo specs, etc.

DCT

 

[Sean Cousins]

Im no tech expert, but I have read that the 1st Gen PCI-E cards are about 4X
faster than AGP X8...depends on other variables tho...mobo specs, etc.

DCT

No, they are not 4X faster. They are capable of being faster but a
current gen PCI-E card is no faster than the same gen AGP card.

 

[Travis King]

No, they are not 4X faster. They are capable of being faster but a
current gen PCI-E card is no faster than the same gen AGP card.

PCI-E will be the way to go in the future. Right now, the performance
difference between PCI-E and AGP 8x is minimal, but when Windows Vista rolls
around, this will be a different story because Windows Vista will take
advantage of the PCI-E unlike XP. Also, a high-end video card will be very
important in Vista if you want the 'eye-candy'. An FX5200 is a bare
minimum, but you should realisticly get something better.

 

[Travis King]

No, they are not 4X faster. They are capable of being faster but a
current gen PCI-E card is no faster than the same gen AGP card.

And you'll want 128MB of video RAM as a bare minimum, but you'd be better
off with 256MB.

 

[J. Clarke]

PCI-E will be the way to go in the future.

Since AGP has been dropped from the Intel support chips and the rest of the
industry has decided not to fight them, that is certainly not arguable, but
it has nothing to do with performance and everything to do with marketing.

Right now, the performance
difference between PCI-E and AGP 8x is minimal,

The performance difference between PCI Express and AGP _4_x is minimal and
depending on which way the bridging goes isn't always in favor of PCI
Express.

but when Windows Vista
rolls around, this will be a different story because Windows Vista will
take
advantage of the PCI-E unlike XP.

Oh? How will it do this?

Also, a high-end video card will be
very
important in Vista if you want the 'eye-candy'. An FX5200 is a bare
minimum, but you should realisticly get something better.

If the "eye candy" in the user interface requires a "very high end video
card" then someone needs to tell Microsoft as they seem to be laboring
under the misconception that just about any current production video board
will support it.

Are you violating your NDA on your Vista beta or just blowing hot air?

 

[J. Clarke]

And you'll want 128MB of video RAM as a bare minimum, but you'd be better
off with 256MB.

And where has there been _demonstrated_ performance gain from this?

Sorry, but you sound like a typical computer saleseman trying to sell an
ignoramus the most expensive video board in the store.