Overclocking:
Overclocking nVIDIA-based cards is easy using the CoolBits registry patch. I recently wrote a guide to using CoolBits and the technique described there is what I used to overclock this card. For this "pushing the envelope" testing, I set the KingMax DDR400 in in the testbed to CAS2 but the testbed is otherwise identical to the tests above. Interestingly, that made quite a difference to even the default benchmark speed. I wonder what kind of system you'd need before the Ti4600 became the bottleneck - clearly our 1.4GHz AthlonXP isn't overly taxing it.

I overclocked the core and memory independently at first. Testing consisted of running 3DMark2001SE's default benchmark and observing if there were any graphical artefacts or errors. The standard memory speed is 650MHz and I was able to get the card to complete the benchmark at 730MHz with no errors. At 735MHz, sections of the screen would flash the wrong colour. This seemed to be towards the middle of the benchmark, perhaps as the RAM heated up - so maybe some cooling of the RAM chips would allow it to go even further. Out of curiosity I let the benchmark at 735 continue despite the occasional error and the score was 9899, LOWER than with the memory at default speed. This is interesting - perhaps the card is having to correct or reset the memory bus due to the errors, which affects performance. So, while you might be inclined to tolerate the occasional graphic glitch in order to have your card on the bleeding edge of performance, it seems you may actually get better performance by clocking it back from the edge a little.

The standard core speed is 300MHz and I was able to run the card at 325MHz - at 330MHz the machine would freeze during the first benchmarking stage. This gave an impressive speed boost also. However, the highest I could run the core and memory overclocked together was 320/730 and this gave the highest score overall. Scores shown are for the 3DMark2001SE default benchmark.

Historically, graphics processors have been starved for data by the RAM subsystem on the card. Bumping up the core speed has often not had much effect as the GPU is unable to pull any more data from the RAM. However, this seems to not be the case with the GF4 Ti4600. Speeding up the core and ignoring the RAM gives a healthy speed boost, more so than the reverse (of speeding up the RAM and leaving the core at stock). Both in combination is best, though. The problem with this is that the core is already running very hot - at default speed the back of the card is not far off painful to touch - and increasing the speed more will make the core run hotter. Asus's cooler is fairly hefty but there's definitely room for improvement and I imagine we'll see more hefty aftermarket chipset coolers appearing as more GF4 Ti's become available.

All up though, as much as I'm committing blasphemy by saying this on an overclocking site, the speed difference we managed to achieve in 3DMark2001SE was only about 2.5%. Given the GF4 Ti4600 (or at least, Asus's implementation of it) is so fast already, it's hard to justify overclocking the card at all.

nView:
One interesting feature of the GeForce4 Ti4600 drivers is "nVIDIA nView", which among other things provides dual-monitor support. Not all cards have implemented this, but unsurprisingly Asus have. They provide an adapter that allows you to connect a normal SVGA monitor to the DVI plug on the card. When you boot with one monitor plugged into the DVI-adapter and another plugged into the normal SVGA port, you are greeted with a wizard to set up nView.

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Dual-monitor support is not too amazingly new these days, but this turns out to be quite a nice implementation of it by nVIDIA. For example, it can be configured to:

• Prevent windows from opening across both screens (or across the join between screens) when your desktop is on both
• Automatically put dialog boxes in the same screen as the application, or the screen where the mouse cursor currently is, or always on one particular screen
• Remember which screen you had an application open on when you last closed it, and reopen it on that same screen
• Create multiple "layered" desktops which can even have different backgrounds, that you can switch between to increase screen real-estate
• Make application and Explorer windows partially transparent (even in Win2K which doesn't natively support transparency like WinXP) to increase your usable screen real estate
• Eliminate extra drawing steps Windows uses for opening, maximising and restoring windows, giving a faster response

I had a decent play with this feature using two 17" monitors and I was very impressed. I've used a similar system on an ATI Radeon 8500DV card and the drivers for that are a nightmare, with simply setting up your desktop across two monitors a very frustrating experience. Not so on the GF4, it was extremely simple and took me literally minutes to be flicking applications from fullscreen on one monitor to fullscreen on the other.

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It's a terrible photo, but hopefully you can see I'm browsing OCAU's news page on one screen and the OCAU Forums on the other. This kind of thing is simple to get going with nView, but true fullscreen gaming takes over the primary screen and blanks the other (so you can't play Q3 on one monitor and read email on another, unless Q3 is running in a window of course). 3DMark had the same effect, but the good news is that the benchmark score was virtually identical to running in single-screen mode. Dual monitor support still has a big cool factor associated with it and to get it thrown in pretty much for free with a high-end 3D card like this is very nice indeed.

nView also provides transparency - you can make windows see-through, so you could for example have a see-through calculator on top of your web browser or something. You can see the entire browser window, while still having access to the calculator app which has a "ghosted" effect. It's the kind of thing probably best explained with a screenshot, so here's an example - I've used the nView menu extensions to set both Calc and Minesweeper to transparent and "always on top", while still being able to surf the net fullscreen underneath.

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Conclusions:
Well, the GF4 Ti4600 has arrived with a bang. Although the speed difference from the previous generation isn't massive, it's an easily noticed improvement. Those who enjoy gaming in high resolutions will notice a big difference even when moving from a GF3, or from earlier cards even more so. Extra features such as the nView dual-monitor support and the prospect of a continued increase in performance as software is written or modified to take advantage of the new chipset make it definitely tempting. Of course, the latest high-end cards always come at a premium price and at the time of writing, with Altech listing this card at $935 RRP the Asus V8640 Ultra is no exception. However, if your budget can stretch to accommodate it and your PC is powerful enough to make good use of it, I say go for it. Blisteringly fast, plenty of features and looks great too - highly recommended!

Many thanks to Altech Computers, a distributor with branches in Sydney and Brisbane, for providing the review unit.