GA-7VRXP: rev. 1.0 or 2.0? And FSB 333?

Mike wrote:
As I understand correctly, the KT333 is just a KT266a with DDR333 support,
right? And that's why it will not support a 166MHz CPU clock. Alltough later
versions of the KT333 do support that.


More or less. Quoting VIA's site:
"Building on the unprecedented power and reliability of the VIA Apollo
KT266A, the VIA Apollo KT333..."
Furthermore they're pin-to-pin compatible so not much in difference
other than the memory speed.

But I read here that the CD will not support FSB333 and the CE will:
http://groups.google.nl/groups?hl=nl&lr=lang_en|lang_nl&ie=UTF-8&oe=UTF-8&newwindow=1&output=search&frame=right&th=d483a10 f6991934d&seekm=E_sQ8.46940%24s82.3743755%40news1. calgary.shaw.ca#link1
I am sorry if I sound stubborn, I am not trying to troll or so, but I am trying
to understand (Technicaly I'm quite a newbie...). Are you sure I have the
KT333CE? The Gigabyte site speaks only of a south bridge CE.

Thanks for your help,
Mike


Yes the CE southbridge should be the VT8233A (the board I have uses the
VT8233 and it's marked as CD). CF will certainly support 166 MHz, as for
CE I don't know but the A7V333 from Asus which also uses the CE revision
is not listed with 166 MHz support (the A7V333-X which uses the CF is).
The 1/5th divider is certainly supported though.

Regards
Nikos

At first, Nikos, thanks for your help!

As I understand correctly, the KT333 is just a KT266a with DDR333 support,
right? And that's why it will not support a 166MHz CPU clock. Alltough later
versions of the KT333 do support that.
[ snip]
Furthermore they're pin-to-pin compatible so not much in difference
other than the memory speed.

I was afraid so...

Yes the CE southbridge should be the VT8233A (the board I have uses the
VT8233 and it's marked as CD). CF will certainly support 166 MHz, as for
CE I don't know but the A7V333 from Asus which also uses the CE revision
is not listed with 166 MHz support (the A7V333-X which uses the CF is).

How do I know for certain which revision I have? I mean, the Gigabyte's site is
not the most trustworthy...

The 1/5th divider is certainly supported though.

Uhhh, do you mean that my chipset *IS* supporting the 1/5 divider necessary to
get a FSB of 333? Mmm, I qoute someone who's saying my bios is not supporting
it...

TIA!
Mike

Mike wrote:

At first, Nikos, thanks for your help!


As I understand correctly, the KT333 is just a KT266a with DDR333 support,
right? And that's why it will not support a 166MHz CPU clock. Alltough later
versions of the KT333 do support that.

[ snip]

Furthermore they're pin-to-pin compatible so not much in difference
other than the memory speed.


I was afraid so...


Yes the CE southbridge should be the VT8233A (the board I have uses the
VT8233 and it's marked as CD). CF will certainly support 166 MHz, as for
CE I don't know but the A7V333 from Asus which also uses the CE revision
is not listed with 166 MHz support (the A7V333-X which uses the CF is).


How do I know for certain which revision I have? I mean, the Gigabyte's site is
not the most trustworthy...


Uncover the northbridge. You could also use a PCI scan tool and obtain a
revision number value, then compare to the value of a known revision.


The 1/5th divider is certainly supported though.


Uhhh, do you mean that my chipset *IS* supporting the 1/5 divider necessary to
get a FSB of 333? Mmm, I qoute someone who's saying my bios is not supporting
it...

TIA!
Mike



From what I gathered, (at least) the CE chipset does have the 1/5th
divider but is NOT certified for 333 MHz bus freq. Your wording is a bit
strange - the 1/5h divider is not a neccesity for 333 MHz bus freq. It
is a necessity for 33 MHz PCI/66 MHz AGP freqs. at bus freq. of 166 MHz.
I see it more as an overclocking convenience - IF you somehow get a
stable 166 MHz bus on a CE revision, THEN you can also have the
possibility to run PCI and AGP at nominal freqs. with the 1/5th divider.
Its implementation or not however by the motherboard maker is a
different story.

Regards
Nikos

Nikolaos Tampakis wrote:
snip
| From what I gathered, (at least) the CE chipset does have the 1/5th
| divider but is NOT certified for 333 MHz bus freq. Your wording is a
| bit strange - the 1/5h divider is not a neccesity for 333 MHz bus
| freq. It
| is a necessity for 33 MHz PCI/66 MHz AGP freqs. at bus freq. of 166
| MHz.
| I see it more as an overclocking convenience - IF you somehow get a
| stable 166 MHz bus on a CE revision, THEN you can also have the
| possibility to run PCI and AGP at nominal freqs. with the 1/5th
| divider.
| Its implementation or not however by the motherboard maker is a
| different story.

Some of my systems use the GA-7VRXP Rev 2.0, and they do not appear to have
any way of setting the FSB clock to 166 MHz. On this board, the FSB clock is
set using a small on-board switch which selects between 100 MHz or 133 MHz -
there just isn't a 166 MHz option available to use. The CPU clock multiplier
is also set by on-board switches, but that is another matter.
The DDR memory clock speed on the GA-7VRXP is set in the BIOS. Either 100
MHz, 133 MHz or 166 MHz can be selected from the BIOS set-up screen, giving
DDR200, DDR266 or DDR333 respectively.
The processor FSB and the memory bus are different and set up seperately -
it is important not to confuse the two.
AFAIK the '333' is the KT333 chipset name refers to the maximum memory bus
speed (DDR333) and not to the processor FSB speed.
Kevin.

Kevin Lawton wrote:
Nikolaos Tampakis wrote:
snip
| From what I gathered, (at least) the CE chipset does have the 1/5th
| divider but is NOT certified for 333 MHz bus freq. Your wording is a
| bit strange - the 1/5h divider is not a neccesity for 333 MHz bus
| freq. It
| is a necessity for 33 MHz PCI/66 MHz AGP freqs. at bus freq. of 166
| MHz.
| I see it more as an overclocking convenience - IF you somehow get a
| stable 166 MHz bus on a CE revision, THEN you can also have the
| possibility to run PCI and AGP at nominal freqs. with the 1/5th
| divider.
| Its implementation or not however by the motherboard maker is a
| different story.

Some of my systems use the GA-7VRXP Rev 2.0, and they do not appear to have
any way of setting the FSB clock to 166 MHz. On this board, the FSB clock is
set using a small on-board switch which selects between 100 MHz or 133 MHz -
there just isn't a 166 MHz option available to use. The CPU clock multiplier
is also set by on-board switches, but that is another matter.

It all boils down to the clock generator installed and its wiring. A
possibility is that Gigabyte used a clock generator that can't be
programmed in the first place for 166 MHz CPU bus output. Another (more
likely?) senario is that the clock generator is capable of 166 MHz
(datasheets for the clock generators are usually available) but the
wiring used doesn't offer the means to program it as such, in which case
some PCB-level action would be necessary to remedy this, more
specifically to isolate the input pins that determine the CPU bus
frequency and supply the required logical 0 or 1 to each to program for
a 166 (or whatever) frequency. There's even the possibility the PCB is
actually ready to accomodate for 166 MHz (in anticipation of 166 MHz
capable northbridges) but they didn't install the jumpers/dip switches
for the proper pins in the clock generator, leaving them instead at a
fixed logical state and only allowing between 100 and 133 MHz selection
for the time.

The DDR memory clock speed on the GA-7VRXP is set in the BIOS. Either 100
MHz, 133 MHz or 166 MHz can be selected from the BIOS set-up screen, giving
DDR200, DDR266 or DDR333 respectively.
The processor FSB and the memory bus are different and set up seperately -
it is important not to confuse the two.
AFAIK the '333' is the KT333 chipset name refers to the maximum memory bus
speed (DDR333) and not to the processor FSB speed.
Kevin.




Yes, that was obviously the original intent. However eventually there
appeared 166 MHz CPU bus officially capable revisions too (CF). I have
no idea how widely they were actually used though.

Regards
Nikos

Some of my systems use the GA-7VRXP Rev 2.0, and they do not appear to have
any way of setting the FSB clock to 166 MHz. On this board, the FSB clock is
set using a small on-board switch which selects between 100 MHz or 133 MHz -
there just isn't a 166 MHz option available to use. The CPU clock multiplier
is also set by on-board switches, but that is another matter.

And I was thinking that when I use a CPU that runs on 166MHz the FSB will
automatically follow to 333. Am I right or wrong?

The processor FSB and the memory bus are different and set up seperately -
it is important not to confuse the two.

Understood. But you are saying we cannot select a FSB or system bus speed on the
GA-7VRXP?

TIA,
Mike

Mike wrote:
|| Some of my systems use the GA-7VRXP Rev 2.0, and they do not appear
|| to have any way of setting the FSB clock to 166 MHz. On this board,
|| the FSB clock is set using a small on-board switch which selects
|| between 100 MHz or 133 MHz - there just isn't a 166 MHz option
|| available to use. The CPU clock multiplier is also set by on-board
|| switches, but that is another matter.
|
| And I was thinking that when I use a CPU that runs on 166MHz the FSB
| will automatically follow to 333. Am I right or wrong?
|
|| The processor FSB and the memory bus are different and set up
|| seperately -
|| it is important not to confuse the two.
|
| Understood. But you are saying we cannot select a FSB or system bus
| speed on the GA-7VRXP?

No - quite the opposite. You can select the CPU FSB clock speed via a
switch - either 100 MHz or 133 MHz, and you can select the memory bus speed
via the BIOS set-up - either 100 MHz, 133 MHz or 166 MHz. That's what I said
and that's how it is. I've used quite a few of these boards recently and if
Gigabyte have come out with a version which will facilitate setting the CPU
FSB clock higher than that then I certainly haven't encountered it. Neither
am I aware of any 'Revision 3.0' or suchlike variant which might support a
higher CPU FSB clock rate.
It is also worth noting that these boards will only support DDR333 memory in
two memory strips, and not three, whereas DDR200 and DDR266 are supported in
all three memory slots.
I felt it worthwhile pointing out that the CPU FSB clock rate and the memory
bus clock rate are different things, as some newsgroup posters seem to
confuse the two. Fortunately, on the GA-7VRXP they can be set independently.
Kevin.

Kevin Lawton wrote:

(snip)

It is also worth noting that these boards will only support DDR333 memory in
two memory strips, and not three, whereas DDR200 and DDR266 are supported in
all three memory slots.

This is a very good point and actually further indication that the KT333
was launched as little more than a quick refix of the KT266A - where
the top priority was (obviously) that board manufacturers be able to
reuse existing KT266(A) board designs...

(snip)

Regards
Nikos

Nikolaos Tampakis wrote:
| Kevin Lawton wrote:
|
| (snip)
|
|| It is also worth noting that these boards will only support DDR333
|| memory in two memory strips, and not three, whereas DDR200 and
|| DDR266 are supported in all three memory slots.
|
| This is a very good point and actually further indication that the
| KT333 was launched as little more than a quick refix of the KT266A
| - where
| the top priority was (obviously) that board manufacturers be able to
| reuse existing KT266(A) board designs...

True . . . . . .
I believe that this process is called 'development' ?
Kevin.

I felt it worthwhile pointing out that the CPU FSB clock rate and the memory
bus clock rate are different things, as some newsgroup posters seem to
confuse the two. Fortunately, on the GA-7VRXP they can be set independently.

OK. So to conclude we have a FSB or system bus speed that runs on either 100 or
133 MHz which can be selected at the board with a switch. We have a memory bus
that runs on 100, 133, or 166 MHz which can be selected through the BIOS. And we
have a CPU clock speed that can be adjusted through the BIOS from 133 to at
least 166 MHz. Am I right?

And a FSB of 166 is simply not possible without alteration of the board, right?

Thanks for the helping this newbie,
Mike