AGP 4X vs. 8X

sundev

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Nov 2, 2004
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My friend just got a X850 Pro, except his motherboard only supports AGP 4X. Does anyone know what the performance difference between 4X and 8X for the X850 Pro (or any similar card) is??

Thanks.
 

moonboy403

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Aug 18, 2004
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well...knowing that he has a 4X slot
i assume that his processor would be MAJORLY bottlenecking his x850 pro
 

secretanchitman

Diamond Member
Apr 11, 2001
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none to very little performance difference. you sure he needs that x850pro? maybe a 6600GT/6800XT will do fine. its going to be severely bottlenecked...
 

sundev

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Nov 2, 2004
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His system is a 2.4 GHz P4, Socket 478 I believe. He doesn't know what motherboard he is using, but is pretty sure it's only 4X AGP capable, and has 512MB RAM.

He got the X850 Pro becuase he got it for a good price, and will be upgrading the rest of his system shortly, and was just wondering how much the 4X would cap the video card performance until he upgrades. So the consensus is that it doesn't affect it very much at all?

He ran 3dMark05 and got a 4200, which is pretty low for a X850 Pro...

EDIT: And he got a 400W PSU, it's generic though. That should be enough right? He has 2 HDs and 2 DVD-RW drives as well.
 

sundev

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Nov 2, 2004
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Anyone know for sure? I couldn't find much info on AGP 4X vs. 8X when comparing newer video cards (I know it doesn't make much difference with older cards like the 9600).
 

n7

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Jan 4, 2004
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Originally posted by: sundevb
Anyone know for sure? I couldn't find much info on AGP 4X vs. 8X when comparing newer video cards (I know it doesn't make much difference with older cards like the 9600).

Read.
The performance hit is minimal, very minimal.
 

sundev

Golden Member
Nov 2, 2004
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Thanks for the link n7. That's what I needed.

So... I wonder what could be causing his low score (4200) in 3dMark05? He ran Driver Cleaner. Could be it be the PSU? I doubt it's the 2.4 GHz P4, even though it's socket 478. His hard drive is fragmented quite a bit, could that be the problem?
 

Wentelteefje

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Dec 6, 2005
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He should try overclocking his P4 a bit, but seeing that his mobo only sports AGP 4x, I don't expect it to have some serious overclocking options unfortunately... Linking a X850 Pro to a generic 400W may be risky, but as long as everything is stable enough, I wouldn't worry... For his next big upgrade, better upgrade that one too...
 

abs0lut3

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Jun 5, 2005
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ghhh...yeah your friend need to buy some decent power supply without risking taking out his x850pro if that generic power supply blows under load. Get some FSP power supply or something. (The P/S) shouldn't be more than 50 bucks but a whole lot of more than a generic 50 bucks P/S that most people sells.
 

OvErHeAtInG

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Jun 25, 2002
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Wentel, there were some good mobo's that only had 4x, for example I just upgraded from the Albatron PX845 PEV Pro, running my 478 at 2.85. That thing was great, even with an 800 XT in it. I don't understand when people say don't run a fast videocard because your CPU will bottleneck it (the horror). As if the videocard will suffocate or something, LOL. A fast vidcard will still raise your minimum FPS even if it doesn't raise your average that much (which is what most benchmarks measure). Actually that's a pretty balanced system (for gaming) - he just needs another stick of RAM.

But yes, the PS is something to be careful of. How many amps does it claim on the 12V and how much does it weigh. Those are the only ways you can usually ascertain the quality of a PSU... Of course if I were you, I'd just run it and see if it blows :)
 

secretanchitman

Diamond Member
Apr 11, 2001
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heh, dont worry about the severe bottleneck. i forgot that im running a p4 2.4 w/HT and 512MB in dual-channel myself...

i would definitely get some brand name PSU though. im kinda afraid that it wont handle the power. maybe a nice 430W or higher would do fine.
 

selfbuilt

Senior member
Feb 6, 2003
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That score is reasonable given the rest of the system. And don't worry about the bottlenecking - look at it this way, your friend can still enjoy cranking up the AA/AF without taking much of a performance hit. As for power supply concerns, check to see if his mobo came with software to monitor the PSU power rails (e.g. Asus Probe on Asus boards is very useful) - if so, monitor the rails under heavy graphics load to see if there's a lot of variability in values. No guarantees of reliability - but significant variation is a pretty good sign the PSU is stressed and at risk.
 

sundev

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Nov 2, 2004
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So his low 3dMark05 score is mostly due to the CPU? Wow, I figured the 2.4 GHz P4 would be fine. It's not the RAM? It's either PC2700 or 3200, he's not sure.
 

TomKazansky

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Sep 18, 2004
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Originally posted by: sundevb
So his low 3dMark05 score is mostly due to the CPU? Wow, I figured the 2.4 GHz P4 would be fine. It's not the RAM? It's either PC2700 or 3200, he's not sure.

2.4 ghz is kinda slow on an intel, fyi.
 

Matthias99

Diamond Member
Oct 7, 2003
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Originally posted by: sundevb
So his low 3dMark05 score is mostly due to the CPU? Wow, I figured the 2.4 GHz P4 would be fine. It's not the RAM? It's either PC2700 or 3200, he's not sure.

If it's PC2700, he'll definitely be hurting. P4s tend to rapidly become bandwidth-starved with slower RAM, since they have a very long pipeline and slow memory causes (relatively) long pipeline stalls. Hence why Intel went to DDR2 already on the newer P4s, while the Athlon64s show little benefit from higher RAM speeds.

Realistically, such a CPU is probably worse than an AthlonXP 2500+ for gaming. In any case, the performance (or lack thereof) is NOT due to the 4X AGP interface.
 

OvErHeAtInG

Senior member
Jun 25, 2002
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Agreed - slow mem is much more likely cause of low 3DM score than a 2.4 P4.

Is this the 2.4c or 2.4b? Dual or single-channel memory controller?
 

DJSfurry

Senior member
Dec 21, 2004
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Hmm.. your friend bought a AGP x850, but plans on upgrading the rest of the system soon? wow.. thats.. not very bright. he shouldve gone pci-e coz now he will be stuck with agp for another couple of years, and will have to change mobos AGAIN in future. bad buy decision IMO
 

thecoolnessrune

Diamond Member
Jun 8, 2005
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Originally posted by: OvErHeAtInG
Wentel, there were some good mobo's that only had 4x, for example I just upgraded from the Albatron PX845 PEV Pro, running my 478 at 2.85. That thing was great, even with an 800 XT in it. I don't understand when people say don't run a fast videocard because your CPU will bottleneck it (the horror). As if the videocard will suffocate or something, LOL. A fast vidcard will still raise your minimum FPS even if it doesn't raise your average that much (which is what most benchmarks measure). Actually that's a pretty balanced system (for gaming) - he just needs another stick of RAM.

But yes, the PS is something to be careful of. How many amps does it claim on the 12V and how much does it weigh. Those are the only ways you can usually ascertain the quality of a PSU... Of course if I were you, I'd just run it and see if it blows :)


QFT. I run a 2.8C w/ HT and the thing is blazing on CPU apps. The crappy little GeForce 4 MX 440 is the thing that slows it down. If I got an X850, I would be slammin :D