re: Twilight Zone type of problem with games, IDE HD and mouse wheel! :)
Tuesday, April 19, 2005 at 1:06 am
Windows XP Annoyances Discussion Forum
Posted by MoonQuake
(5 messages posted)
That's a nice and complete reply, Jack!
I never came close to the first line of your reply in term of help looking on google
or irc. Thanks
I forgot to mention my CD and DVD drives. :)
Thing is, I got a good PSU: Antec TruePower 450. I thought I was good with this.
Maybe it's the power cables like you said so I'll check all this.
So you say that I should have all my HD on separate cables? Cause I think I got both
HDs on the same cable, and both CD/DVd on another one.
I'll check this out and give you some news about it.
Last question: how could I send more juice to the 12v IF my mobo BIOS doesn't allow
me do it? And If I'm allowed to do so, how much of an increase should I look for?
Thanks a million!
MQ
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On Monday, April 18, 2005 at 7:29 pm, Jack Gulley wrote:
>Gee. You listed the specifications and talked about every thing but the most
logical
>thing that is causing the problem!
> The problem is your POWER SUPPLY and its +12v power distribution!
> I bet you have a CD-RW and/or DVD/RW in there that forgot to mention. Plus a
few
>FANS and maybe some neon lights running off of +12v. But with two disk drives (and
>maybe some CD/DVD drives) and all that hardware on a P4 processor, plus that Video
>card, your system is going to draw a LOT of current at +12v. The "weak" point of
>most cheap power supplies.
> Here is what happens. When you roll the scroll wheel, the processor loads down
>sending commands to the video graphics adapter to start scrolling the screen up/down.
>This processor activity starts loading down the power supply some. The Graphics
Processor
>then goes into overdrive moving all that data around, and it in turn starts drawing
>a large amount of current. That is why they get hot and have to have a fan. This
>huge increase in load on the power supply forces it to redirect more of its power
>to the critical +5v and the voltages to the processor, system board and video adapter.
> Because the +12v is less critical and less regulated, input power is taken away
>from it and shifted to the other voltages, causing the +12v to drop slightly. With
>a slight lag, this voltage drop causes the fans and motors running off of it change
>speed and in so doing, draw even more current on the +12v. On some machines you
can
>actually hear the power supply fan change speed when scrolling the screen up and
>down this way. Actually what you are hearing is the change in beat frequency between
>different speed fans. All this current draw takes the +12v down just a little more
>and induces a little ripple on the +12v as the power supply struggles to recover
>from the change in loads. After some delay, it recovers and is able to bring the
>+12v back into regulation.
> But guess what the most sensitive device in the system to +12v ripple is? You
>guessed it, the disk drives. When they see the +12v drop to far and then ripple
on
>the voltage, they start cutting back their power draw on +12v, and the only way
>they have to do this is cut back power to the motor control logic, which causes
their
>motors to spin down. It is normally the last drive (least used) drive that will
start
>to spin down first.
> Now complicate this with the fact that most of the wires going to the disk drives
>are too small of a gage and too long to carry current when there is ripple on it,
>and most power supplies have several connections drawing current on each leg out
>of it, no wonder the disk drives are spinning down.
> If you look at the top of the line power supplies sold, they have a higher rated
>maximum current on the +12v than do most other power supplies. In addition they
usually
>have only one connector that can plug in to a disk or CD-Rom drive per leg and have
> more legs out for this, plus a heavier gage wires, so that current draw and ripple
>are not such a problem.
> OK, so what can you do? Well you could get a much better power supply, one rated
>at a higher output with a lot more current (amps) on the +12v. And that has more
>legs out of if for powering drives, fans, etc. The quality of power supplies is
judged
>more by their total weight than by their price. OR, you can try to make sure nothing
>else (fans) is plugged into the legs going to the disk drive. You can turn off some
>of the load on the +12v if you have neon lights in the box and extra fans. Maybe
>even unplug a DVD or extra CD-RW drive. You can even help the power supply by using
>a good quality power cable to it (instead of the cheap small gage wire ones that
>come with some systems). And make sure it is plugged directly into a wall outlet
>or heavy gage distribution box, and not hooked up through some cheap long extension
>cord and switch box. A good quality UPS box sometimes helps as they usually have
>heavy gage short cables.
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