AGP Performance: 8x vs. 4x

[SanTropez1971]

I have a problem. I have just ordered both a new Intel 850e board with RDRAM PC1066 and a Radeon 9700. The Radeon 9700 is an 8x AGP card but will run at 4x. I wanted the best perforamce system available and this was it until I remembered the AGP 8x. It seems this is the ONLY feature I am missing. I coulse have gone with the new Via board that uses DDR400 and had AGP 8x but I was a bit sceptical.

So my questions are...

Should I keep the Intel 850E board but take the hit on performace by running the Radeon 9700 at 4x?

Or

Should I return the 850E board an go with the VIA DDR400 solution which comes with AGP 8x?

Also...

What kind of lose in performance should I expect from running this Radeon 9700 at 4x over the optimal 8x?

Ati was sorta able to assist me with this. Here is a quote.

"Regarding "Ok, I am stressing here. I ordered a new Radeon 9700 to go in a new system I am building. The only problem I have is that my new (Intel 850E RAMBUS) system only has AGP 4x not 8x. I am guessing that the 9700 is backaward compatible? If so how much performance would I really be loosing? I can either bag my RAMBUS setup and go with a new VIA board that has AGP 8x if it is really that important.


The Radeon 9700 can work at multiple speeds, from 2x to 8x and this can be changed to what ever speed you would like the card to function at and it is backwards compatible. In terms of performance from 4x to 8x, i have tried to find answers to that question but the only information that i was able to find is on the web page, and the link is right bellow:

http://www.ati.com/support/faq/agpchart.html

Please verify with your motherboard specification to meet the cards requirements. I have found a link to the motherboards manufacturers:

http://www.ati.com/support/info/motherboardmanufacturers.html


Regarding "Also if money is not an object will the Fire GL X1 be better than the regular 9700 in PC gaming?":

The Fire GL x1 is targeted for computer that are doing graphic designers, video editing/rendering, and 3D animation. If you are interested in playing games with your system, i would suggest that you stay with the Radeon 9700, it will function faster than the Fire GL X1"


<P ID="edit"><FONT SIZE=-1><EM>Edited by SanTropez1971 on 08/15/02 09:13 AM.</EM></FONT></P>

 

[Crashman]

The i850E with PC1066 will stomp the P4X400 in performance. As for a performance loss using 4x instead of 8x, I doubt one will exist with the 9700, graphics technology prior to the 9700 couldn't even use all the bandwidth AGP4x had to offer, so even though the 9700 will use more bandwidth, it won't be that much.

A perfect example is when AGP4x was introduced. At that time the fastest card you could buy was the TNT2, which was available at AGP4x. Well, AGP4x did nothing for the TNT2. It did nothing for the GeForce 256. And it did so little for the GeForce2 GTS that the BX chipset (AGP2x) could outperform the best AGP4x chipset of the day, the i815, with that card! And that was in graphics benchmarks and games.

So does the Radeon 9700 need AGP 8x for best performance? The truthfull answer is probably that AGP8x will do absolutely nothing for the 9700, just as AGP4x did nothing for the TNT2 or Geforce. At best it does very little for the 9700, as AGP4x did very little for the GTS.

So your best performance answer is to stick with the 850E and PC1066. AGP8x at this point is nothing more than a catch phrase, just as ATA133 is now and AGP4x was for two years. VIA is capitalizing on selling garbage chipsets with these "new features" that do nothing to help you, such as ATA133, AGP8x, and DDR333 for the Athlon.

<font color=blue>You're posting in a forum with class. It may be third class, but it's still class!</font color=blue>

 

[SanTropez1971]

This is a great response. Thank you for taking the time to go over this for me. Your time and knowledge is really appreciated. Do you actually work for this website?

 

[Crashman]

lol, not yet!

<font color=blue>You're posting in a forum with class. It may be third class, but it's still class!</font color=blue>

 

[lhgpoobaa]

lol... u could allways go work for btvillarin's webby

<b>Before visiting THG i was a clueless noob. Now im still clueless, but look at my nice title!<b>

 

[deadkenny]

I don't actually agree that PC1066 performance will "stomp" "400" DDR performance. It might still be better, but "stomp" is massively overstating the difference. This wouldn't be part of your anti-Via 'crusade' now, would it? Anyway, I agree that the 850 chipset is a good solid chipset (like the "BX" of P4 chipsets). RDRAM still has the bandwidth advantage, due to the lack of dual channel DDR boards. However, also keep in mind that DDR has a latency advantage of RDRAM, so that also factors into it. I also agree that you've summarized the AGP 4X vs. 8X issue very nicely. Intially there should be little difference in real performance, in spite of the theoretical advantage of 8X.

That (upgrade) which does not destroy you(r system's stability), makes it stronger. Nietzche

 

[JaeSun]

check out Shuttle's mobo:

<A HREF="http://www.spacewalker.com/english/mainboard_detail_info.asp?number=196" target="_new">http://www.spacewalker.com/english/mainboard_detail_info.asp?number=196</A>

AGP8x, DDR400 support (unofficial) ... may not be as fast as RDRam1066, but pretty close....

and i agree with deadkenny...RDRam doesnt Stomp DDR, it may be a bit faster, but not enough to stomp it....

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[Crashman]

er, I need a job that pays the rent, thanks.

<font color=blue>You're posting in a forum with class. It may be third class, but it's still class!</font color=blue>

 

[Crashman]

OK, how's this for mental math: The 645DX beats the P4X333, the P4X400 performs the same as the P4X333, the 648 performs the same as the 645DX, therefore the 648 should have no problem beating the P4X400. And since the i850 beats the 645DX, the 645DX beats the P4X333, and the P4X400 matches the P4X333, the i850E stomps the P4X400. If you really want to save money by using DDR400, and you really are fooled into believing there is a benifit right now in AGP8X, you'd be better off with the SiS 648 than the P4X400. But since there isn't, blah blah blah, i850E/PC1066 wins.

<font color=blue>You're posting in a forum with class. It may be third class, but it's still class!</font color=blue>

 

[deadkenny]

I don't see any 'math' at all in your post. Check out the actual benchmarks between the Intel 850 chipset and SiS 648. I already agreed with your point about AGP 8X being of limited advantage at this point. The real benefit will only come in the future. If you check my original post, I wasn't saying that any DDR solution is better than PC1066, merely that 'stomps' is a huge overstatement of the difference. It's a little like saying one ball club 'crushed' another, when they won by one run in extra innings. If you want to impress me with some 'math', then you'll have to post some numbers, like benchmarks. Check out the review of the SiS648 chipset right here on Tom's. BTW the title is "DDR 400 Kills Rambus".

That (upgrade) which does not destroy you(r system's stability), makes it stronger. Nietzche

 

[SanTropez1971]

I am confused. I read the artice on DDR400 with the SiS board but when I go to SiS's site (to look at the chipset) and the Asus site (to look at the P4S8X) they both only talk about DDR333 with no mention of DDR400. So where is this chipset that Tom was talking about? It is the same chip, SiS648?

http://usa.asus.com/mb/socket478/p4s8x/specification.htm

http://www.sis.com/products/chipsets/oa/pentium4/648.htm

<P ID="edit"><FONT SIZE=-1><EM>Edited by SanTropez1971 on 08/15/02 10:03 AM.</EM></FONT></P>

 

[AMD_Man]

Check out the review of the SiS648 chipset right here on Tom's. BTW the title is "DDR 400 Kills Rambus".

DDR400 is right in between the performance of PC800 and PC1066 RDRAM. That puts it within 2% or so of either RDRAM speed. I can personally guarantee you won't notice a 2% difference in performance jumping from PC800 to DDR400 and then another 2% to PC1066.

<b><i>"A penny saved is a penny earned!"</i></b>

 

[deadkenny]

Reviews often come out based on pre-release samples. I'm not even sure if '400' DDR is an officially recognized standard yet. At this point '400' DDR is probably just OC'd '333' DDR. Mind you, SiS has done this before. When they first came out with the 645 chipset, it ran the memory at '333' before there was an officially recognized standard for that.

That (upgrade) which does not destroy you(r system's stability), makes it stronger. Nietzche

 

[JaeSun]

it doesnt "officially" support DDR400 ... JEDEC hasnt even approved DDR400 specs (another words, there is no official DDR400 out there...its all essentially overclocked DDR333 right now) ....

crashman, go read around, THG, anandtech, hothardware ... all have reviews or links to reviews....benchmarks, everything, it all shows that DDR400 is very close to Rambus1066 ..... a couple areas, it falls behind, but for about 90-95%, its very close, if not on top ..... RD1066 doesnt stop on DDR400 .... your math is wrong, as Sis648 outperforms Sis645/DX pretty well ......

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100 Character Limit Sucks!!

 

[deadkenny]

Thanks, pretty much what I thought. As I said, SiS 'jumped the gun' previously with the 645 chipset and 333 DDR support (i.e. before 333 was official) and it looks like they've done it again with this chipset.

That (upgrade) which does not destroy you(r system's stability), makes it stronger. Nietzche

 

[JaeSun]

i also read that by the end of the month, Sis should have another chipset, Sis648DX, which will officially support DDR400...read somewhere at www.anandtech.com in the news section...linked to www.digitimes.com i remember ...

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100 Character Limit Sucks!!

 

[juin]

add this P4X400 dont work with stable operation with DDR 400 also there latency It higher that Pc 1066.Overclocking aceshardware was able to overclock it over 160 mghz so very near the Pc1333 level (if that standart will..you know) they also just maybe be lucky with there rimm

The day i meet a goth queen that tell me Intel suck.I turn in a lemming to fill is need in hardware.<P ID="edit"><FONT SIZE=-1><EM>Edited by juin on 08/15/02 11:07 PM.</EM></FONT></P>

 

[Crashman]

Titles are deceiving, as that one was meant to be, it pointed out that DDR400 only beats PC800 RDAM. And for overclockers it gets even better, PC1066 beats DDR400, and has the ability to be overclocked!

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[lhgpoobaa]

just out of scientific curiousity... how far can you push that PC1066? and what brand is best?

<b>P4 'Wilty' Celleron 1.7, 128Mb PC100 Cas3 SDRAM, 5400rpm HDD, Integrated everything. YUM!<b>

 

[Crashman]

The speed of Kingston chips is 32ns, which allows speeds up to PC1200 to fall withing spec (150x4 bus speed, x DDR)

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[deadkenny]

I agree that the body of the article did not support the supposition that 400 DDR 'kills' Rambus. Again, my only point is that your statement to the effect that PC1066 'stomps' 400 DDR is a huge overstatement of what is in fact a small difference (with RDRAM admitted with the bandwidth edge, but at a latency disadvantage compared to 400 DDR). BTW, it's not 400 DDR, or even 533 DDR that's going to 'kill' Rambus. What will ultimately kill Rambus will be mainstream dual channel DDR mobo's. Right now RDRAM has the bandwidth advantage over DDR, but that's only because RDRAM is running on dual channel boards compared to DDR on single channel boards. If you put DDR on a dual channel board, then it crushes RDRAM in bandwidth, as well as having a latency edge. Intel already has a dual channel DDR server board, so it does work (no way Intel would try and market a server board that wasn't stable - that's their bread and butter). But I'm guessing it's still too expensive for the desktop market, or other manufacturers (other than Intel) are having trouble implementing it. Or, if you're into conspiracy theories, maybe Intel is not coming out with a dual channel DDR desktop board in order to 'buy some time' for Rambus.

BTW, great exchange of different opinions without 'flaming' or personal attacks. Keep up the good work all.

That (upgrade) which does not destroy you(r system's stability), makes it stronger. Nietzche

 

[JaeSun]

exactly..been to other boards where it turns into nothing but flames ...sucks ...

anyways....thats all we saying, basically what deadkenny.. RDRam doesnt kill us. quite honestly, in my opinion, i think RDRam wont be here in a couple years, unless something happens. ever since intel turned their back to them, its kinda been downhill for them. theyve had to turn to other companies (i think SiS?) to keep them afloat. and the fact that it remains pretty expensive for the most part, and that DDR is an alternative cheaper, yet close performance solution, makes it harder for RDRam to compete.

yea, dual channel will be the stuff. sometimes, i almost feel tempted to wait until that comes out to try it out. but then again, i dont want to wait too long...so far, this is what i be getting for my comp that im building:

Shuttle AS45GTR (supports Serial-ATA, RAID, USB2.0, AGP8x, Firewire)
P4 2.53Ghz 533FSB
512MB Corsair XMS DDR 400 PC3200 CAS2 Ram
ATI Radeon 9700Pro /or\ nVidia NV30 (core) made by Leadtek
Win98SE/Win2000Pro
Silver Chieftec Aluminum Server Case w/ Window
2 Western Digital Caviar Series 40GB

the DDR-II is very promising and tempting ..... if it comes out by jan-feb, then i can probably wait until then, since im not in *TOO* much of a hurry to get my new computer. i mean, 2.53 chips are expected to fall to around $243 in the end of sept when the 2.6/2.8 gets released. and also since Sis648DX is to be released, id like to wait on that, even though shuttle's board is very good with features and performance. i just hope shuttle comes out with one with the 648DX. and also, waiting would be good, so that the boards can be tested for awhile in the market. but the main thing for me, Sis648DX, or even better, waiting for DDR-II.

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100 Character Limit Sucks!!

 

[xxsk8er101xx]

I wouldn't worry about it. You won't even notice a difference!

<A HREF="http://www.anandtech.com/mysystemrig.html?id=9933" target="_new"> My Rig </A>

 

[SanTropez1971]

back on the topic of my original post check out this reply from Ati. Did you guys know that you have to call a toll number for support on an Ati product for the first 30 days? Then after the first 30 days you have to call a 900 number and pay $1.25 per minute for help. This is total crap. During my call to Ati I told them that as long at that policy was in effect I would no longer buy Ati products. Please everyone voice your concerns to them. I don't think you should have to pay to talk to an actual human on a product you just spent $400 on (Radeon 9700).

[E-Mail Reply from Ati Starts here]

Regarding "No.. more like strangle. I was thinking that the 4x AGP bus would put a cap on the performance of this card due to the need for an 8x bus. But I have heard from a few people that the need for AGP 8x on this card for actual performance increases may not be a necessity. Take a look at this URL and tell me what you think":

Certainly that when the card is running at 8x, the overall performance will defenitely increase. Once Direct x version 9.0 is out, it will take full advantage of Direct x features, there fore giving you better quality in game play and graphics and above all performance.

[E-Mail Reply from Ati Ends here]

 

[Crashman]

LOL, that sounds like the DX7 argument for the GeForce, it just didn't come true.

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