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AGP Bus - 4x vs. 8x

Discussion in 'Computers' started by Diallo B, Feb 5, 2005.

  1. Diallo B

    Diallo B Screenwriter

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    folks,

    for the last couple of days i have been trying to find out if there is a good reason for me to change my motherboard from a 4x AGP to an 8x AGP.

    i need a better video card so that i can play hd video and also play world of warcraft and i plan on getting the ati radeon 9800 pro. but my current motherboard only has 4x agp as i am using a ati radeon 7000 with only 32mb of ram. the 9800 pro is backward compatible but would i be losing much?

    i have been to tom's hardware and a couple of other reputable sites but i can not get any definitive information.

    can anyone point me in the right direction?
     
  2. WayneO

    WayneO Supporting Actor

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    I don't have a place to get a definitive answer, but as a member of various PC forums, I've come across threads about it in the past. The general consensus was that performance wasn't hindered that much at all. Now with more current games, it might be more prevailant.
     
  3. Tekara

    Tekara Supporting Actor

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    The quick answer is No.

    The reason is that the AGP bus is used when your video card runs out of memory and is forced to use the system memory to store texture information. And if this happens, there will be a massive slowdown in spite of using AGP 4x or 8x. So basically, you don't want to make the video card use the system memory and as a result there's no difference between AGP 1x, 4x or even 8x.
     
  4. Diallo B

    Diallo B Screenwriter

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    thanks wayne and rob.

    does anyone else have any other facts/opinions/experience with this issue.
     
  5. Harris_C

    Harris_C Stunt Coordinator

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    Diallo,

    From my experience, there is a small performance increase depending on the application or game that you are playing, but nothing significant.

    AGP 4X has a maximum bandwidth of 1066 MB/s while 8X has a maximum bandwidth of 2133 MB/s. However, with a 9800 Pro you have 21760 MB/s of bandwidth on the card itself, as well as 128 MB of RAM. Games always run best when the majority of textures are all stored in video RAM, as even the fastest external interface is relatively slow. Some motherboards - particularly with VIA or SiS chipsets - have problems running AGP 8X, so dropping down to 4X can improve stability at the cost of *maybe* 2 or 3% performance.

    Overall performance is based on quite a few factors, therefore I would be more concerned with loss due to other components(i.e not enough RAM, Old MOBO etc.) than the AGP bus.
     
  6. Scott L

    Scott L Producer

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    Using the benchmark programs I saw a big difference in going from a 4x mobo to 8x. But again, this is for gaming. There's other things that usually come with an 8x AGP bus like side-band addressing and fast writes, 2 technologies just about all current AGP cards use.
     
  7. MikeH1

    MikeH1 Screenwriter

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    I have used them synth tests to and have changed things to see what the performance increase/decrease was. Not so much for AGP but other things.

    Here's my experience with 3d Mark 2001.

    P4 2.0 Ghz
    512 Ram
    1024 X 768 Resolution
    AA off, AF off
    Geforce 4 Ti 4600 - 3 tests ran that worked out to an average of 11 000 marks.

    Bought a new card a year later, the Radeon 9800 pro. Wanted to see how it compared to my old card. All the varibles I kept the same, except of course the card.

    average of 12 000 marks.

    For a card that I thought would be *that* much better it really didn't show it in 3D marks. I unhooked my second moniter to see if that would help clear up some processing power, I actually scored a little lower. Strange. Overclocked my card, no real difference in marks. Perhaps in game though it would make a difference but a 2 - 5% possible increase in frames doesn't really warrent the extra work the card does IMO.


    But in game (Battlefield 1942) the differences were more day and night. I could never play on a server with acceptable FPS of more than 40 people with the Ti 4600. ANd when a lot of action happened, framerates dropped and the card would start chugging a bit through the heavy action scene.

    The 9800 pro allowed me to play on 50 player servers quite easily. And, when there was a lot of action, I would notice the card *want* to start chugging but it was kind of weird, the best way to explain is that its like it dropped a gear and kicked up the rpm's too make up for it and rendered these graphicly heavy scenes rather flawlessly.

    I use 4 X AGP and was asking a friend the very same question your asking here the other night and he said what others have, thats its not much of a difference at all.

    I just use them synth benchmarks to give me an idea of what should be acceptable marks and to make sure everything is running top notch. If I were to run it today and notice a 20% loss then I would know something was up. I'm not like one of those guys on Guru3d.com that spend more time trying every little new driver out and tweaking it and pushing their system to the max. Over their, its all about bragging rights but it is a goldmine of information regarding hardware and especially video cards/drivers.
     
  8. Diallo B

    Diallo B Screenwriter

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    thanks for the info mike.

    i picked up my 9800 pro today and installed it. the install went fine and everything is up and running. i ran through some demos and it is readily apparent that my system is alot different than when i was running the radeon 7000.

    as i type this on one monitor, world of warcraft is installing on the other monitor. i am actually making a gaming only partition on my computer. the only thing that i have installed on it is xp pro sp2, applicable drivers and warcraft. i think that this will improve the performance of the system while gaming as there is absolutely nothing running in the background.

    i can't wait to see the difference with the 9800 vs. the 64 mb nvidia geforce 4 i was playing warcraft with on my laptop.
     
  9. MikeH1

    MikeH1 Screenwriter

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    World of Warcraft is great, I've been playing that too lately.

    Watch the default drivers that come with the 9800 (are they the 3.4's ?), good drivers are a must and hundreds can be found at Guru3d. Personally I use the 4.6, yes their a little dated but it runs BF series games great. I have tried others but have had texture issues and Crash to Desktop.

    The rule with video card drivers is that always having the latest version is not such a good idea. Drivers work differently for everyone, if you find some that run your particular game(s) well, stick with them, even if they are a year old or so. I go about changing mine every 6 months or so, but first I read the driver forums on Guru to see what the benchmark junkies are saying about them and which games run good. Like I said, you can learn a lot over at that site. Also, theres a lot of not so good drivers out there...

    I couldn't be bothered wasting my time trying out new drivers every week to keep updated, just to have a CTD. If it ain't broke, I don't fix. Saves me time, headaches and most importantly keeps me in game [​IMG]
     
  10. Diallo B

    Diallo B Screenwriter

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    well folks after playing for a couple of days this 9800 pro is everything that i wanted. it is in the 4x agp slot and everything is fine. with world of warcraft, i have all of the settings maxed out and am playing at 1024 X 768 with absolutely no lag or choppiness. everthing is great!

    edit: i bumped the WoW resolution up to 1280 X 1024 and everything is still running smooth.
     
  11. Phil Kim

    Phil Kim Stunt Coordinator

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    Wait few months for PCI Express (and selection of graphics card) to become more prevalent.
     
  12. Diallo B

    Diallo B Screenwriter

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    why do you state this?
     
  13. MikeH1

    MikeH1 Screenwriter

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    I'm maxed out too, I just keep AF low in the game options.

    The only real lag I experience is sometimes in the cities, Ogrimmar for instance. Since a lot of players are hanging out near the bank and Auction House which are very close together (and the city obviously has a lot of detail to render) I tend to get some chop chop but in a game like WoW it don't really matter to me.

    PCI E x 16 is going to be the new AGP for video cards. Its a much better, efficient way of tansmitting the bus data. To put it in perspective, imagine AGP sharing a lane with other PCI. PCI E will have its own dedicated lane and thus be faster.

    This can explain it better.
     
  14. Diallo B

    Diallo B Screenwriter

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    i understand in theory why pci x is better. but apparently in real world operation while the lane is bigger the information transfer will never be large enough to utilize it.

    as someone has already stated even the fastest cards nowadays barely use over 4x. so what's the big deal?
     
  15. Chris

    Chris Lead Actor

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    While this is true, the big deal is a matter of efficiencies. PCI-E provides better output for power to the newer, power hungry cards.. (and if you're on the AMD64 side, you can make use of PCI-E/SLI which is it's own trick)

    Boards with AGP8X generally have faster signalling within the northbridge on the motherboard, this is provided by better chipset makers (Intel, Nvidia, etc.)

    This means that not only is their a figurative "wider lane" to your CPU, but that it's more efficient, and therefore less processor intensive, to get the data there. This is true of AGP8X vs. APG4X in better chipsets, and true of PCI-E vs. AGP8X.

    Because PCI-E provides an easier access to information then AGP, it makes new generation PCI-E cards cheaper then their AGP8X cousins at the high end.

    It also introduces the possibility of something we are just starting to see.. PCI-E cards with no native memory that pull from the system memory.. I think one of the first examples of that will be the Nvidia 6200 TurboCache cards.

    Anyway, for what you are after with a 9800 Pro, you're mostly fine.. the biggest benefits of an AGP8X board aren't just the faster AGP8X standard, it's part that.. but mostly other features which became common (integrated NIC in the southbridge which uses less CPU and no PCI interface, like Nvidia's NF controller or Intel's CSA; USB2.0 on the motherboard; etc.)
     
  16. Scott L

    Scott L Producer

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    Echoing Chris, I believe you WILL see a performance increase if you go with a modern 8xagp motherboard. If only because the latest designs and chipsets are much more efficient. Out of personal experience going from an Asus P4PE to a P4P800 I noticed a difference.
     
  17. Diallo B

    Diallo B Screenwriter

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    now i am even more confused. this thread is about to take a turn though.

    i thought that i was computer literate/savvy and i understand everything that has been stated here. but my question comes from this here:



    my 4x agp board includes an integrated NIC, usb 2.0, integrated ac-3/5.1, integrated firewire and a couple of ohter things. so, is it common a common occurence that most 4x boards do not have these ammenities?
     
  18. Chris

    Chris Lead Actor

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    Correct. The vast majority of boards that top out at AGP4X do not support USB2.0 or better NICs.

    And, while your board does have an integrated NIC, your NIC is going to be "integrated" in the sense that there is a chip on your board that acts as a PCI NIC. Whereas, on newer boards, like Intel's CSA series and Nvidia's Nforce3/4 boards, the NIC is integrated into the southbridge, meaning that it has more bandwidth available to it (not necessary for most home users) and requires less signaling and therefore, much lower CPU usage.. which is a good thing [​IMG]
     

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