Please read also the important update from November 13!
Introduction
The following article doesn't result exclusively from our own work. Basically there were some factors which made us thinking about and investigating. The starting point was our i845 review, where we mentioned by the way that the i845 chipset supports both AGP 4x und 2x graphic boards, but only with a voltage of 1.5 V. As its big brother i850 can only handle AGP 4x graphic boards as well, this was not surprising and we first of all didn't pay further attention to this matter.
The following supplement to an EPoX press release, concerning the launch of the EP-4B2A motherboard based on i845 "Brookdale", made us prick up our ears and lead us to post a corresponding news:
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"The Pentium 4 Chipsets i850 & i845 only support 1.5 volt 4x AGP.
Older chipsets (e.g. VIA 693 and Intel BX) support 3.3 volts AGP 2x, however newer chipsets are downward compatible to 2x/4x (e.g. 815EP, 815EP B stepping and VIA 694X) and support 3.3 volts as well as 1.5 volts.
This does not apply to the Pentium 4 chipsets because the i850 und i845 only support 1.5 volts graphic boards (regardless of 2x or 4x). Therefore the 3.3 volts 2x VGA graphic boards cannot be installed in a Pentium 4 system any longer.
The graphic board as well as the motherboard will be destroyed after installing a 3.3 volt graphic board. EPoX grants no guarantee in these cases of user's own faults. You find a corresponding hint to the 1.5 volts graphic boards on the pages 1-5 of the P4 user's manuals | |
Well, a reader's email, reaching me after the publication of this press release, set me thinking because Michael put his finger on the problem: Exactly which graphic boards are concerned and which may be installed?
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"Hello,
nice that this issue is pointed out in the article.
Is this only relevant to EPoX boards? After all this chipset is used on other boards as well.
Maybe a list (or a diagnostic tool) should be created to find out which graphic boards are concerned, as my user's manual (Creative GF2 GTS) doesn't provide any hint regarding 1.5 volts or 3.3 volts.
Therefore I think that many users don't know which voltage is required by their graphic boards.
Finally, one can't trust each word of one's dealer or seller - very often the support of 'normal' users is insufficient. So I sent you this mail as you may be able to achieve something for the general public."
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I promised Michael to look after this issue. At least I thought that it could be possible to write a report regarding some concerned graphic boards, when a further official press release, dealing with this matter in detail, reached me from EPoX. While compiling the necessary information, we came upon a fact that unexpectedly complicated matters. But let's start at the beginning - what's it about anyway?
Please read also the important update from November 13!
