What's the performance diff between a 4x and 8x APG?

[meckeard]

Is there a big performance diff between a 4x and 8x APG slot?

I have a Mobo with a 4x AGP running a 4/8x video card and want to upgrade for gaming reasons and was wondering if an 8x AGP Mobo would give me an instant boost.

Thanks,
Mark

 

[bcastner]

Negligible difference between 4x and 8x.

Moving to a faster process is a different fish. The gains can be substantial.

 

[Crowley16]

not sure about that, what ram do you have on the gfx?

if you've got very small amout of video ram, then the performance difference can be rather significant cos you'd be looking up system memory on every cache miss...

considering most 3d games will easily take over 100megs+ of video ram nowadays, the 8x might improve performance significantly, of course there's a LOT of other things to consider as well...

Although if you're thinking of upgrading, then why not get a pciE, that's got 16x gfx channel...

--------------------
Procrastinate Now!

 

[LloydSev]

AGP8X (AGP 3.0) is the next generation VGA interface specification that enables enhanced graphics performance with high bandwidth speeds up to 2.12GB/s and twice as fast as AGP4X.

In its initial implementation, PCI Express can yield transfer speeds of 2.5G bit/sec in each direction, on each lane. By contrast, the version of the PCI architecture that is most common today, PCI-X 1.0, offers 1G bit/sec in throughput. PCI Express cards are available in four- or eight-lane configurations (called x4 and x8). An x4 PCI Express card can provide as much as 20G bit/sec in throughput, while an x8 PCI Express card can offer up to 40G bit/sec in throughput.

The PCI Express* x16 graphics interface, offered by the Intel® 925X, 915G and 915P Express chipsets, provides a solution for demanding usage models. The PCI Express x16 graphics interface delivers increased bandwidth and scalability over previous generation AGP8X-based solutions. With up to 4 GB/s of peak bandwidth per direction, and up to 8 GB/s concurrent bandwidth, a platform configured with a PCI Express x16 graphics card can tackle the most demanding multimedia tasks.

Computer/Network Technician
CCNA

 

[meckeard]

I have a GeForce4 4200 TI w/128 megs of RAM. Since I want to start upgrading my PC and the MOBO is the first item, I was curious about any performance gain I would see.

Thanks.

 

[LloydSev]

as bcastner pointed out... it has to do more with a combination of your parts, then just the video card and speed..

you have to take into account the agp or pcie slot speed, the cpu, system ram, fsb, etc...

Computer/Network Technician
CCNA

 

[bcastner]

As expected, AGP 8x can safely be considered a marketing feature for now. Although it sounds impressive, it offers no real benefit for the current generation of games. A GPU like the GeForce4 MX440 would be unable to handle the amount of data the 8x interface is capable of supplying anyway, and it would be much slower than the on-board memory as well. The most telling sign that the switch to AGP 8x is more of a calculated marketing move than a push for desperately needed hardware resources is the fact that the only two NVIDIA cards that are being "upgraded" to the new interface are also the company's mainstream cards, the best sellers MX440 and Ti4200, while the heavyweights Ti4400 and Ti4600 remain unchanged.

http://www6.tomshardware.com/graphic/200210041/

Will the AGP 8X provide twice the amount of raw gaming and/or application performance seen in AGP 4X? No, it won't even come close at this point in time. To AGP 8X's defense however, the technology is not being billed as the savior of graphic solutions. Nor are there any claims that AGP 8X will deliver twice the performance of an AGP 4X video card. Still, we have to take into consideration that current applications simply are not optimized for the newer spec, or drivers, and even hardware for that matter. I think as time passes, benefits from the technology will eventually materialize to a greater point than where they are now, but by that time, we may very well be gearing up for AGP 4.0 / AGP 16X.

http://www.devhardware.com/c/a/Video-Cards/AGP-8X-A-Closer-Look/

The fact is that little was every realized for 8x, and essentially the issue is superceded with PCIE. The gains from a 4x to 8x move is negligible, or worse.

 

[meckeard]

I wanted to stay with AGP because I won't be upgrading my card immediately. Besides, I'm not totally sold on PCIE just yet, as I have heard many different points of view.

Just as an FYI, here are my PC components:

Dell 4550 Mobo (4x AGP)/case/power supply
P4 2.66 ghz
512 meg DDR 400 RAM
GeForce4 4200 TI w/128 megs of RAM

Mark

 

[LloydSev]

regardless.. PCI Express is probobaly where the market will be going anyways, away from AGP. AGP 8x is not worth the upgrade as Bill pointed out.

Computer/Network Technician
CCNA

 

[cdogg]

As bcastner and others have pointed out, the interface grows in bandwidth, but the video card and software itself is the limiting factor.

The truth is that they could make newer cards in either AGP 8x or PCI-E, and you wouldn't see a difference. I have heard that the newest of video cards like ATI's Radeon x800 series or Nvidia's GeForce 6800 GT series, truly relies on the extra bandwidth. If synched down to AGP 4x, some say that there is a slight drop in overall performance, indicating that AGP 4x's bandwidth limit is being exceeded.

With that said, the debate here doesn't really matter. Any new board you go with has AGP8x or PCI-E support. Plus, any newer card you would buy supports one or the other. Therefore, the only decision you need to make is which one.

Since you don't want to upgrade the card now, then go with an AGP 8x board. New cards will continue to be released in this format for at least then next 1 - 2 years if not longer...
=======================================================

If you are asking whether or not your AGP 4x GF4 video card will somehow perform better on the 8x mobo, the answer is no. The CPU, RAM, and FSB if increased/upgraded would be the deciding factor.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
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