Subject: Re: supported 3.3V PCI cards (sound and TV)
To: Emmanuel Dreyfus <>
From: Chuck Swiger <>
List: netbsd-users
Date: 02/11/2006 09:03:28
Emmanuel Dreyfus wrote:
> What 3.3V PCI sound card supported by NetBSD are available? 
> Is there any brooktree-based 3.3V PCI card on the market? Any 3.3V TV
> card (with any chip, not only brooktree) at all?  

Almost all modern PCI 2.x cards will be 3.3V or universally keyed; 5V cards are

> And, if someone knows, why is there two signaling standards (5V PCI and
> 3.3V PCI)? Is it just to make my life more complicated?

Historically, all TTL signals used 5V logic, but over the past five or ten
years, newer devices running at higher speeds needed to reduce the voltage to
keep heat at tolerable levels, so CPU, memory, and bus voltages have been moving
towards 3.3V or 2.5-2.7V signal levels.

5V TTL signals have a better fan-out, which is why motherboards used to be able
to hold eight or even 16 RAM slots; nowadays, there are plenty of motherboards
which can't actually drive even four RAM slots at full rated speed.