Re: Only 10 MB/sec with via 82c686b chipset?

egger@suse.de
Wed, 21 Mar 2001 18:34:40 +0100 (CET)


On 21 Mar, Jonathan Morton wrote:

> The "blue and white" PowerMac G3 and certain early PowerMac G4s used a
> 66MHz PCI card for graphics in lieu of proper AGP. 66MHz PCI is used
> in certain high-end workstations, as well, but it's not normally found
> on consumer-level devices.

> Look at 'lspci -vvv' output for the "66MHz" flag on the devices listed
> there - all the ones in my Duron system leave it unset, except for my
> (very recent and pretty nippy) SCSI controller and (AGP) video card.

Well, I wasn't talking about 66Mhz nor about 64bit cards but rather
normal consumer cards which are specified for 33Mhz.

> That said, *most* PCI devices don't like being overclocked, and it's
> not well known that pushing the system bus also pushes the PCI and ISA
> buses in the same manner. A friend of mine had *severe* locking
> problems with his system when he inserted his cheap SCSI adapter into
> his overclocked machine, even though the other cards handled it OK
> (relatively speaking - I'm not convinced). I don't know how far he'd
> overclocked it, but 37MHz kinda rings true.

Trying to enhance a systems performance by overclocking the bus is
about the most stupid thing one can do as one ANY of the connected
devices memory/CPU/chipset/PCI devices/AGP cards (just to name a
few) have a high probability of failing and all those probabilites
factor up which basically means that the system is in a unpredictable
state which is never acceptable for any serious kind of system.

Better leave the overclocking of busses to kids who are bored
by their live.

-- 

Servus, Daniel

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