PCI vs. AGP 8x?

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Alien

I want to buy a 256mb card, can anybody tell me if there is a
difference in performance between a PCI and AGP 8x card if they have
the same specs?
 
Alien said:
I want to buy a 256mb card, can anybody tell me if there is a
difference in performance between a PCI and AGP 8x card if they have
the same specs?
Click to expand...
Are you refering to PCI or PCI-Express? If you are refering to PCI,
absolutely. The PCI bus is 33mhz, the AGP bus is 66mhz so AGP8X is
533mhz effective. If you are refering to PCI-Express, also yes. The
PCI-E bus is 75mhz so a PCI-E x16 slot can max out at 1350mhz effective.
Keep in mind that PCI-E hasn't been fully utilized yet by games but is
the best option for future proofing.



Am I Batman or Superman? I'm so confused.
 
Are you refering to PCI or PCI-Express? If you are refering to PCI,
absolutely. The PCI bus is 33mhz, the AGP bus is 66mhz so AGP8X is
533mhz effective. If you are refering to PCI-Express, also yes. The
PCI-E bus is 75mhz so a PCI-E x16 slot can max out at 1350mhz effective.
Keep in mind that PCI-E hasn't been fully utilized yet by games but is
the best option for future proofing.



Am I Batman or Superman? I'm so confused.
Click to expand...

PCI-E is 100mhz.
 
Batman or Superman wrote:


-- snip -- -- snip --
Am I Batman or Superman? I'm so confused.
Click to expand...



Here take this, writes "my name is The Joker" on a card.
Put this card in your pocket so you don't get confused.
:)
 
Well, we seem to have gone off on our own little "thing" here. I think I
know what you're asking, and I think I know what you're wondering.... As
best I can tell you is, "IF" your CPU is an athlon XP NOT 64 bit, and at
least 1.8ghz or better, as mine is, an XP2500+, you are trying to decide to
jump to an athlon 64, or keep your current system and get an AGP card. Well,
we are stuck in a dillema. Do we shell out big bucks to jump to 64 bit? Or
stick with our 32 bit systems for a while longer? I decided to stick with my
2500+ <overclocked to between 1.9 and 2.2ghz, depending on my mood and what
I'm playing> And I just bought a Sapphire X800 GTO 8x agp with 256 meg of
ddr3 ram. It replaced a 9800 pro 128. I am MORE than satisfied with it, as
it boosted my gaming performance, and benchmarks by a ballpark average of
5000 points in aquamark3d and 3dmark 03. And, I can run D3 at 1280x1024 4xaa
@ high quality and get 55-70 fps and BF2 at a little lower resolution and
get between 60 and 90 fps. <haven't had the card long and I'm still playing
with resolution, refresh rates, quality settings etc etc.
I'm not ready to pluck down $600 for a mobo, cpu and video card, and windows
XP64 for a few pfs.....
I'm not really sure if this helps you, but, if this answers your question,
thats good. Everyone else went off on a techno band...... It is so
frustrating because everyone came out with new technology, and, it requires
us to totally rebuild our rigs, and, we're not even sure what's gonna stick
around, whats gonna bomb, what is really best, etc etc etc. I read
MaximumPC, and I read they built a dual EVERYTHING PC. dual dual core
processors, 4gb of ram, 4 TB of disk space, dual 7800 GT video cards in SLI,
the rig cost about $12,700 and change.....
But, alot of games and programs are not written for dual cpu's, let alone
dual core cpu's yet.... so, there is such a thing as overkill when it comes
to upgrading your system. I dont think they've come out with a 64 bit
edition for BF2, D3, Q4.... get where I'm going? Good luck bud. Check out
that card, I think you'll be happy with it. I know I am :)
--
{SFU} Jackyl

MSI K7N2 Delta ILSR
Athlon XP2500
ATI Radeon X800 GTO 256
1gb Geil DDR 3200 DC
 
The said:
That is throughput, and it is "A single lane is capable of
transmitting 2.5Gbps in each direction, simultaneously."
http://arstechnica.com/articles/paedia/hardware/pcie.ars/5

I'm talking bus speed and my mb's bios tells me it is running at
100mhz, that's how I know.

PCI = 33mhz
AGP = 66mhz
PCI-E = 100mhz
Click to expand...

If Ars Technica is claiming that for throughput Ars Technica is in
error--the clock speed is 2.5 GHz, the encoding is 8/10B so you get 80% of
that, or 2 Gb/sec.

PCI Express is not a bus in the conventional sense, it is point-to-point and
serial--each lane is two pairs, one transmit and one receive, and each
running on a 2 GHz clock. If it was running at 100 MHz then it would have
less throughput than Fast Ethernet.

If your motherboard is reporting 100 MHz for PCI Express then it's reporting
something other than the lane clocking, probably the clocking of the
parallel bus going into the bridge.

Take a look at <http://www.intel.com/technology/pciexpress/devnet/> and
<http://zone.ni.com/devzone/conceptd.nsf/webmain/605EFE8126ED4DB686257014006BC124>.
 
If Ars Technica is claiming that <snip>
Click to expand...

They're not. It corroberates precisely what you say. If necessarily
lengthy, it is a well written article which explains PCI evolution and
PCIe operation in an interesting, clear and easy to follow manner.

"A link that's composed of a single lane is called an x1 link; a link
composed of two lanes is called an x2 link; a link composed of four
lanes is called an x4 link, etc. PCIe supports x1, x2, x4, x8, x12,
x16, and x32 link widths.

PCIe's bandwidth gains over PCI are considerable. A single lane is
capable of transmitting 2.5Gbps in each direction, simultaneously. Add
two lanes together to form an x2 link and you've got 5 Gbps, and so on
with each link width."
Copyright © 1998-2005 Ars Technica, LLC

Really thanks to all involved in this discussion. As a consequence of
it I'm now far better informed of the FACTs re PCIe myself.
 
If your motherboard is reporting 100 MHz for PCI Express then it's reporting
something other than the lane clocking, probably the clocking of the
parallel bus going into the bridge.
Click to expand...

What's this article talking about then?

http://www.nbsgaming.com/PCIEBus.html

The other day while scouring my bios for some random item I found a
rather nostalgic setting that took me back to the good old days when I
used an AGP video card. This setting was the PCI-E bus frequency. In
this little menu you have the option of taking your standard 100 MHz
PCI-E bus and increasing it to upwards of 145 MHz...
 
The said:
What's this article talking about then?

http://www.nbsgaming.com/PCIEBus.html

The other day while scouring my bios for some random item I found a
rather nostalgic setting that took me back to the good old days when I
used an AGP video card. This setting was the PCI-E bus frequency. In
this little menu you have the option of taking your standard 100 MHz
PCI-E bus and increasing it to upwards of 145 MHz...
Click to expand...

What part of "probably the clocking of the parallel bus going into the
bridge" did you have trouble with?
 
What part of "probably the clocking of the parallel bus going into the
bridge" did you have trouble with?
Click to expand...

"Probably" isn't conclusive. That's the problem I have with it.
Provide some hard data.
 
The said:
"Probably" isn't conclusive. That's the problem I have with it.
Provide some hard data.
Click to expand...

The "hard data" is that PCI Express moves 2 billion bits per second on a
single pair with a 2.5 GHz clock and 8/10B encoding. Every technical
discussion of PCI express by any company that actually makes the chips that
support it explains this.

Whatever is clocked at 100 MHz on the nforce4 chipset is not the PCI Express
lanes unless _you_ can explain how they get 2 billion bits per second on a
single pair with a 100 MHz clock and 8/10B encoding and why Intel and
National Instruments and the rest are wrong and some random overclocker is
right.
 
The "hard data" is that PCI Express moves 2 billion bits per second on a
single pair with a 2.5 GHz clock and 8/10B encoding. Every technical
discussion of PCI express by any company that actually makes the chips that
support it explains this.

Whatever is clocked at 100 MHz on the nforce4 chipset is not the PCI Express
lanes unless _you_ can explain how they get 2 billion bits per second on a
single pair with a 100 MHz clock and 8/10B encoding and why Intel and
National Instruments and the rest are wrong and some random overclocker is
right.
Click to expand...

You really believe that some chinese workers can come up with some 2,5
Ghz Maiboard, which is gigantic in comparison to the worlds famous cpu
makers, struggling around 3 Ghz on highly integrated chips ?

Come on...
 
Thomas said:
You really believe that some chinese workers can come up with some 2,5
Ghz Maiboard, which is gigantic in comparison to the worlds famous cpu
makers, struggling around 3 Ghz on highly integrated chips ?
Click to expand...

???? PCI Express was not created by "some chinese workers". The first
chips that supported it came from Intel.

The whole point of it is that a single pair can be clocked much higher than
a parallel bus. Those 3 GHz microprocessors have to keep 64 signal lines
synchronized at that speed, where PCI Express only has to worry about one
line at a time. 10 gig Ethernet gets 10 billion bits per second to go 40
kilometers on a single optical fiber and they've demonstrated 40 meters on
CAT5E cable in the laboratory--2.5 billion for a few inches on circuit
board traces isn't all that much of a trick.
 
The "hard data" is that PCI Express moves 2 billion bits per second on a
single pair with a 2.5 GHz clock and 8/10B encoding. Every technical
discussion of PCI express by any company that actually makes the chips that
support it explains this.

Whatever is clocked at 100 MHz on the nforce4 chipset is not the PCI Express
lanes unless _you_ can explain how they get 2 billion bits per second on a
single pair with a 100 MHz clock and 8/10B encoding and why Intel and
National Instruments and the rest are wrong and some random overclocker is
right.
Click to expand...

My mb uses a ULI chipset and it says right in the bios - PCI-E clocked
at 100mhz.
 
The said:
My mb uses a ULI chipset and it says right in the bios - PCI-E clocked
at 100mhz.
Click to expand...

Which means that either (a) that clock speed is not the lane clock or (b)
your board is only able to run PCI Express at 5% of the rated speed.
 
Which means that either (a) that clock speed is not the lane clock or (b)
your board is only able to run PCI Express at 5% of the rated speed.
Click to expand...

It's the frequency it runs at, not the throughput. WTF would it say
100mhz if it doesn't run at a frequency of 100mhz? Is the mb
manufacturer on drugs or are you?
 
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