SIS735/745 vs. VIA KT266A/333 in PCI bandwidth comparison

[Duffman]

Hi, I just read this in www.ocworkbench.com forum and thought this will be interesting to many of you.

quote:

"I got to test the SiS735/745 in the context of my work. We're developping video editing platforms, and these babies are real PCI-bandwidth hogs. (720 x 240 pixels x 60 fields per second is a lot of data!)
We wanted to support AMD AthlonXP CPUs really hard, since these processors are amazing computing powerhorses. However, the Via chipsets clearly held the platform back, with PCI bursts scoring no higher than 40 MB/s when two bus master devices try to perform simultaneous transactions (IDE does count for one!). This could get pretty technical, but let's just say that in these particular tests, Via scored 40, Intel 90 and SiS managed to pull out an amazing 92 MB/s burt rate (out of a theoretical 128 MB/s).

Before someone asks about the Via issue, YES, this relates to the PCI latency bug Via has acknowledged recently, and NO, it cannot be fixed by a software patch like they would like you to believe. The PCI core has an hardware bug, and no driver nor bios update can fix this. Also, since the new KT333 will have the same PCI core as the KT266A, PCI bandwidth will be no better in the newer chipset.

That being said, KT266A/KT333 platforms perform just fine when equipped only with an AGP card looping Quake3 demos. That's exactly why most hardware review sites sing praises for the KT266A. But, honestly, is this really all you intend to do with your computer ? Not me "

[Gator]

WOOHOO! Happy Sis735 chip owner right here!

thanks for the info, VERY interesting

[wwchan]

Re: SIS735/745 vs. VIA KT266A/333 in PCI bandwidth comparison

Originally posted by Duffman
Hi, I just read this in www.ocworkbench.com forum and thought this will be interesting to many of you.

quote:

"I got to test the SiS735/745 in the context of my work. We're developping video editing platforms, and these babies are real PCI-bandwidth hogs. (720 x 240 pixels x 60 fields per second is a lot of data!)
We wanted to support AMD AthlonXP CPUs really hard, since these processors are amazing computing powerhorses. However, the Via chipsets clearly held the platform back, with PCI bursts scoring no higher than 40 MB/s when two bus master devices try to perform simultaneous transactions (IDE does count for one!). This could get pretty technical, but let's just say that in these particular tests, Via scored 40, Intel 90 and SiS managed to pull out an amazing 92 MB/s burt rate (out of a theoretical 128 MB/s).

Before someone asks about the Via issue, YES, this relates to the PCI latency bug Via has acknowledged recently, and NO, it cannot be fixed by a software patch like they would like you to believe. The PCI core has an hardware bug, and no driver nor bios update can fix this. Also, since the new KT333 will have the same PCI core as the KT266A, PCI bandwidth will be no better in the newer chipset.

That being said, KT266A/KT333 platforms perform just fine when equipped only with an AGP card looping Quake3 demos. That's exactly why most hardware review sites sing praises for the KT266A. But, honestly, is this really all you intend to do with your computer ? Not me "

According to techchannel.de http://www.tecchannel.de/hardware/817/index.html
this problem is resolved by the following RPP patch http://www.viaarena.com/?PageID=66#raid

[Ratchet]

I was thinking about upgrading my motherboard and moving away from VIA due to some of the problems with it (not the least of which is that PCI latency issue mentioned). Any recommendations for a quality SiS motherboard? I'm partial to ASUS, Abit and now Soyo, but if there's someone else making good SiS mobos thn I'd like to hear it.

[highpingdrifter]

had no problems with the k7s5a from ecs ,the only problem is it is definitely no overclockers board but i hear the k7s6a is better equipped for overclocking

[Duffman]

hmm...so that VIA PCI latency bug is fixed, eh? oh, well, i guess that's it, then.

Still, if SIS chipset interests you, i guess one would go for 745(DDR333) chipset rather than older 735. I read 735 had a some sort of bug when overclocking.

For 745 chipset, ECS K7S6A came out first and is probably cheapest now. Then there is MSI 745 Ultra and ASUS A7S333. According to the response from people who actually used these boards, AUSUS boards is not that better than MSI's. There is review of MSI 745 Ultra at www.ocworkbench.com and if you go to forum you can read user responses on these boards. It seems ASUS did not give out samples of A7S333 to benchmarking sites, so English review of this board is hard to find.

Aopen also has 745 board AK75pro which implemented FireWire integrated in the chipset and another version without FireWire. They just came out so reviews are nowhere to be found.

These boards seems to have no onboard stuff integrated, like LAN, RAID, and 6ch sound. They just have basic AC97 codec for sound.

One 745 borard has RAID controller and CMI8738 sound chip which is Chaintech 7SJR, you can find a review also at www.ocworkbench.com

Keep in mind that the SIS745 chipset do not support neither ATA133 nor USB 2.0. KT333's southbridge don't have USB2.0 controller but the board makers seems to include separate chip to support this. That is, if you care for these features at all.

Other well known board makers like Epox and Gigabyte is supposedly coming out 745 board but if it didn't come out by now, it may well be not coming out at all. who knows...

[chemmajik]

The MSI SIS745 Ultra is the best right at the moment for top speeds, its having less issue's then the Asus. Also it runs fine at 166/166 where the K7S6A still hasnt gotten a bios fix yet. A friend will be shooting for 183/183 in the next few days or go for 200 with new ram coming in. But if your cheap the ECS K7S5A has good performance & stability just get a decent PSU with it.

[9-Bar]

i've just built a pc for my bro, with MSI 745 Ultra, excellent board, i'm deffo gonna consider a SiS, for my next chipset,
had a prob setting up memory at first, but sorted it after a bios update....

[mulciber]

Originally posted by 9-Bar
i've just built a pc for my bro, with MSI 745 Ultra, excellent board, i'm deffo gonna consider a SiS, for my next chipset,
had a prob setting up memory at first, but sorted it after a bios update....

I should be getting that same MSI 745 board tuesday glad to hear its liked. Ive been having too many problems with my Epox 8kha+ board that its just time to throw in the towel

[9-Bar]

yo mulciber, if you have a prob with board when rebooting it keeps knocking back the fsb to 100, when u have a 133fsb xp chip, grab the new bios from MSI....

this solved my prob and is in the description of the fix in the new bios anyway... apart from that, enjoy!!!!

i've put it through benchmarks and wot not, sucess on everyone, and performa better than my KT266A in a lot of cases