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Ok, Mike...
Just wanted to let you know I successfully over clocked my new G4/733 Silver
tower to 800Mhz last night. It was so incredibly easy, it was ridiculous.
You've GOT to have good eyes, but the actual over-clocking couldn't have
been
easier if it had a dial :)
Here's the scoop. If you look closely at the directions and CPU speed
choices
on the Japanese page, you'll notice that the new 733 is the ONLY CPU that
can
be over clocked WITHOUT SOLDERING A RESISTER! In fact, 800Mhz is the only
choice
if you don't want to mess with soldering!
So, I took out an incredibly sharp razorblade, and simply cut the solder
leads
on each side of the resistor marked R3. This causes the transistor [resistor-Mike] to fall
off
the board, effectively setting the CPU for 800Mhz.
[Note: Actually an even easier way I have used is just to cut the one trace leading from the resistor, which
is easier to undo (bridge it over with solder or conductive pen) and doesn't require removing the resistor.
Trace Cut Method for 800MHz Setting
(G4/733 Digital Audio CPU Module)
The image above shows a Digital Audio G4/733 example of the trace cut method. I have not seen a QS G4/733 to know if the PLL CFG resistors are the same layout/position.-Mike]
One interesting thing to note about the new Quicksilver machines is THEY ARE
LOUD! They have FOUR Fans! One for the CPU (thats new... it's rubberized and
attached next
to the massive G4 heat sink), [note - the Digital Audio G4s also have a
cpu fan, at least on the Dual G4/533 and G4/733 models. I've not seen the
466 and single G4/533 to see if they do also.-Mike] One for the Case (same as before), One for the Power Supply, and One for my Geforce3!!!!!
[UPDATE: A different reader sent his Quicksilver Fan Noise Reduction Mods-Mike]
Anyway, I digress...
I bolted everything back up, prayed to the Gods of Computer Heaven, and hit
the power button on my Cinema Display.
wait... wait... wait... "Chime"
:) Sweeeeet!
OS 9.2 boots... I see the desktop... everything looks great... but did it
change the clock speed? I go to the Apple Menu, launch Apple System Profiler... and...
YES! 800Mhz!
:)
So now, the only question is stability. I think it's working pretty good.
(I haven't tried the Geforce3 yet.. still has the stock GeForce2MX card).
I played Quake3 (cg_drawFPS = 1 turns on FPS)... I saw an average of 30-60
fps at 1600x1200 with all options on. On 1024x768 (which I don't like because it
stretches the image on my Cinema Display) it was 70-90fps, with an
occasional
100+fps :) I played Quake3 for 2 hours, did some Bryce Rendering, etc... no
lockups.
I've got a Sonnet RAID/66 card with a 160Gig Stripe set in the machine, and
set to have
file sharing on for the other Macs to access. They stayed connected all night long, and
it didn't crash last night. So, that looks promising.
I'll need to test Photoshop on a big 200 meg file or so and see if that will kill it.
Also, I'm going to try and download a CPU temp. program and see if it is overheating.
But with all the fans, I don't think it will be :)
One note of interest...
On the Stripe pair, with the ATTO benchmark, at 733Mhz I was getting Read
times of 110MB/s SUSTAINED at 512K sizes. Set to 800Mhz, I'm only getting 90MB/sec. Wonder
why that slowed down?
[I also suggested Richard try ATTO tests with the 8MB I/O setting, since the 512K setting is well within the Hard Drive's cache size and is not a real indicator of sustained (to the platter) disk performance.
Also running any benchmarks or tests only after a clean reboot is best, since that assures the most consistent/repeatable system/ram/cache state for comparison purposes. -Mike]
Hmmm....
But so far, everything seems faster, the Bryce Rendering was faster, Quake3
& Unreal
Tourney is faster (NEVER saw the fps hit triple digits at 733, it does every
now and
then at 800)... but hard disk access may be slowed just a tad. Wonder why?
Anyway, thats all... thought you'd like to know.
The cool thing is it was so easy... just slice the two solder leads on
either side of the resistor, and *BOOM* an extra 67Mhz. No messy soldering, no ruining
the CPU, just quick and easy... and most importantly... seemingly STABLE 800Mhz!
I think owners of 733's are lucky. No L3 cache speeds to worry about.
Remember, if the CPU is fine being over clocked, but the L3 cache isn't, then BOOM, you still have a frozen sad Mac! :)
:)
Cheers...
Richard H.
Sales Engineer
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