P4 motherboard bus ratios, specifically SiS645

[Lord Evermore]

I'm trying to decide which P4 motherboard I want to get. I'd prefer to get a SiS645-based board than an i845D. I'm thinking either the EPoX 4SDA+ or the MSI 645 Ultra. However NO reviews I've found on either board mention the bus ratios (only saw one review of the EPoX so far), and no posts on message boards. I assume that this is because you can't change the ratios, that it's done automatically, but since nearly every review mentions motherboard overclocking capabilities, I don't see why they wouldn't point out that you're going to be stuck at certain ratios with certain FSB speeds. Reviews of other boards point out whether you can change the ratios.

Has ANYBODY seen any mention of this? Or anybody have these boards and able to test it?

 

[THUGSROOK]

im using an Asus P4S333...

bus ratios are auto.
i was able to run 120fsb all the way to 132fsb w/o any pci problems, so the divider must be kickin in there at some point.
either that or my system can run a 44mhz pci bus :Q
...and i seriously doubt that

 

[Lord Evermore]

Well that's my point. If the divider is going to kick in to a 1/4 at 120MHz for PCI, that's going to give me only a 30MHz PCI bus. And at 132MHz that comes to near as makes no difference to spec 33MHz. I'd rather not have it automatically do that, I'd rather see how I can do with it running at 1/3. Especially with a 133MHz bus, I'd want to have a 1/4 divider kick in, since then everything would be to spec (except the CPU of course).

 

[THUGSROOK]

if you are planing to put a northwood 1.6/1.8 on that board you will most likely make it to 133fsb anyways.

 

[Lord Evermore]

I know I probably will. I just want to make absolutely sure of how the ratio's are going to work. I also just can't understand why NOBODY mentions the issue.

 

[Syntax]

Check out the P4S Soyo Dragon Ultra. SIS 645 plus a ton of other features. You will find reviews on Reviews

 

[THUGSROOK]

Lord Evermore -
its almost as bad as the memory multiplier/dividers

 

[THUGSROOK]

oh hey some good news.... i can verify for sure that the agp bus DOES NOT kick back until 133fsb an a p4s333.

 

[exp]

<< only saw one review of the EPoX so far >>


Here are some more 4SDA+ reviews for you.

 

[Lord Evermore]

thugsrook: I'm not sure that's really good news, since that means the AGP bus is running at a whopping 88MHz until you hit 133FSB. I would also assume that if the AGP isn't kicking back, then neither is the PCI.

I'd seen the Soyo P4S as well before and thought it looked really nice. I know already that SiS's onboard Ethernet controller is good (using a K7S5A right now), and USB2.0 would be good, but not exactly a requirement. That's pretty much all I'd use on that board, especially if I made it my main system (which I'm considering if I can make it run really well). However the nearly DOUBLE price over the EPoX board doesn't seem justified to me. I'll use the onboard sound most likely for either board if the system is just doing DVD decoding for me and to play with, but if I made it my main system I'd swap in a Santa Cruz (assuming I like it when I get one tomorrow) or a Live!. So the extra features of the onboard sound of the Soyo aren't a big selling point. Neither is the 133RAID controller, as I have no desire to attempt IDE RAID again, nor do I need it. ATA133 would be nice in and of itself, but it's not a requirement, and certainly not worth the price increase.

 

[Lord Evermore]

Weird, when I replied to this post, the forums gave me an error that the attempt had timed out after waiting 60 seconds, but then the post still showed up. But then in the thread list, it still showed exp as having been the last to post.

Anyway, I read all the reviews of the Soyo and the EPoX board. STILL I'm not totally sure about the issue. Not a single one mentions the ratios for the EPoX board. Only ONE shows a CMOS settings screen for the Soyo, where it shows a setting for AGP/PCI and it's set to Default, but then the author just completely skipped describing that setting so I don't know what the options are or what the defaults are.

I have to wonder if this is just total laziness on the part of the authors. If the manual doesn't point it out and mention it, do they just not think of things they need to look for? Maybe a sign that there's too damned many cheap hardware review sites that people have just thrown together that really don't have any business doing hardware reviews (or reviews of any kind really).

Funnily, one mentions that he put the FSB to 150MHz, but "they say that XP doesn't support that high frequencies" so he had to reduce it to 145MHz. Since when does the operating system "not support" faster processors? (Aside from the AMD/Win95 bug which was not an issue of "support".) And who's "they" that say this?

 

[dAv]

Here's the specs on the Gigabyte GA-8SRX:

The DDR, AGP and PCI voltage can be adusted +.01v .02v and .03v independent of each other.
CPU clock is adustable 100-200 1Mhz at a time
The DRAM, AGP and PCI can be adusted up or down independently, with the CPU
clock setting affecting the ratios. For instance:
CPU 150
DRAM 300 250 225 200 187 150 125 120 112 107
AGP AUTO(?) 100 75 60 50
PCI AUTO 37 30 25

CPU 100
DRAM 202 176 166 151 141 133 126 121 100 88 84 80 75 72
AGP AUTO 66 50
PCI AUTO 33 28 25

VCORE is adustable up to 1.85v

Here's the only review I can find Link

 

[Lord Evermore]

<< There are no any non-unsoldered elements on the board. >>



I just found that line from that review humorous. A triple negative. I have no idea what the reduced phrase means, "there are no soldered elements...".

I may consider the gigabyte, if I happen to see it. Price and specs are comparable to the EPoX. I'm somewhat partial to EPoX though as I loved my SS7 board from them, but my roommate never got his Gigabyte Athlon board working properly with a GF2MX video card.

Where did you get the specs about the AGP/PCI dividers? That review didn't mention them.

 

[68GTX]

Here's another review of the Gigabyte GA-8SRX

 

[dAv]

The specs on the AGP/PCI dividers is from my computer BIOS screen.
Currently running 150 150 75 37 1.6v. Crucial 256 2.5 PC2100
Boot screen shows FSB as 149 - 2.38Ghz!
Stable running Prime95

 

[Lord Evermore]

I'm pretty much sold on the Gigabyte since it seems to be the ONLY board, aside from the far more expensive Soyo, that has the ratio's even defined, let alone controllable. Of course, NOBODY at the local computer show this weekend has the MSI, EPoX or Gigabyte boards, only one had a Soyo (they had other P4 options from those brands, just not the one I want). I assume this is in large part due to supply issues, the local shops are low on the totem pole since they'll only order a few at a time.

Nobody had any P4 A-spec's either, at least not many. Only a couple had any 1.7A or 1.8A, and nobody had 1.6A, and as usual, they cost more than I could get them from newegg even after shipping.

In the end I just got another heatsink for my Athlon. I meant to get some AS3, but forgot about it. Then I went to CompUSA and picked up several things. Got a Santa Cruz (the only place at the show that had SC's was selling them for 10 dollars more than CUSA; imagine, CompUSA being CHEAPER than somebody else!).

 

[Insane3D]

Lord Evermore -

I'm in the exact same boat as you. I'm looking to pair a 645 board with a 1.6A for some o/c goodness, but the reviews of the mainstream boards are severely lacking in my opinion. I was worried about the same issues as you since I will be using some Crucial that will do 160mhz or so, and I wanted to be able to run a 1.6A @ 150mhz FSB while having my memory at the same speed. After seeing the posts on the Gigabyte, I am going with that. I was heavily leaning on the Epox, but it is still unclear if it supports the bus ratios. The Gigabyte looks nice and it's cheap! Only $80 @ Mwave.. Thanks for the thread!

 

[o1die]

I fixed the sound issue, but it wasn't that easy. I had to install the game before installing the sound drivers. Runs ok now at 138 fsb with 1/1 cpu/mem ratio at the fastest memory settings. Hopefully, I won't have any more sound issues with other games. My system is running smoother today, so I won't say any more unkind words about the sis 645 chipset. Hopefully, sis will address any issues in a timely manner. I could not access their website.

 

[Regalk]

Same here - been reading lots of reviews - some saying that the 645 boards can make it to 133 and beyond, some vague some not using the 1.6A or 1.8A
So far:
Reviews are not focusing on:
NW 1.6A or 1.8A
Vcore adjustments or mods
DDR voltage
Cooling (everyone appears to be using Intel retail HS)
AGP/PCI specs at various FSBs
Memory speeds at various FSbs (especially if using PC2100)

Most reviews seem to be half-a$$ed so far and bent on giving scores!!
AND I despise guessing games

 

[Lord Evermore]

o1die: that's kind of a random post.

What "sound issue"? (If you put it into another post, I probably didn't read it.) The SiS645 doesn't have sound built in. Any sound issues are due to problems with that particular motherboard design, using an external sound chip built onto the board, not problems with the SiS chipset. Or, god forbid I suggest this, maybe even a software issue, not hardware design; or worse, user error.

You're the first person to ever say "stay away from SiS645", and it's basically invalid reasoning for it. As far as I've seen, NO ONE has had any problems or incompatibilities with any SiS645 board. It scares me to think someone might ask you which chipset to go with.


Regalk: I can understand reviewers not going into EVERY possible detail. Like testing what effect voltage adjustments have on overclocking, there's just too many combinations for them to do it all, and there's really not much point -- we all know increasing voltage is probably going to increase overclocking ability. But the fact is they're leaving out basic stuff about what is and is not available on the board; when they discuss overclocking, they need to discuss what options are there, whether they actually test those options or not.

But, pretty graphs and numbers are what people want to see, so they give the audience what they want. I'd bet a huge number of the hits are from people that really don't know what they're doing, it's their first time building a system, they want to seem l33t by knowing some stuff but couldn't handle real details.

 

[mbf]

I don't know if I'm pointing out the obvious here, but whenever I'm shopping for a new board I usually start by dropping by the manufacturer's website, where you can usually download a PDF version of the manual. This won't tell you about stability or overclockability, but you can usually find some decent explanations of the board's capabilities, as well as a lowdown on the BIOS settings.

 

[Lord Evermore]

EPoX does not have the manual available yet for their board. MSI's doesn't mention it. Didn't get Gigabyte's yet. The MSI manual does not mention the PCI/AGP ratios at all. Generally that's expected, if they simply don't have an option to change them, and technically the board is only rated to run at one FSB speed, they're not going to tell you what will happen if you overclock it.

 

[dbwillis]

Ive no problems with the sound on my P4S333..still running strong at 2304mhz-144fsb-144ddr (1:1 ratio+fast timings)