by Sergey Lepilov
08/04/2006 | 01:36 PM
In my recent article called New CPU Coolers Tested: Zalman CNPS8000 and Scythe Mine (SCMN-1000) Review I stressed the fact that the growth of heat dissipation of CPUs has not only stopped, but changed into a decline. Unfortunately, I can’t say the same about another very important computer component, namely the graphics card. Alas, graphics cards need ever more power and produce ever more heat. At Computex 2006 the leading GPU manufacturers said that next-generation graphics cards would require as much as 130-300W of juice, and so a 1000-1200W power supply would have become necessary by the end of this year!
It is to cool the graphics card that Zalman, the manufacturer of various cooling systems, has released its new VF900-Cu LED for. Owners of the Zalman VF700-Cu can notice the change of only one letter in the model name while the word LED means the highlighting of the fan (but there are models with a highlighted fan in the 700 series, too). Despite these inconsiderable discrepancies, the two cooler models are completely different products. The new VF900-Cu LED is to be correctly viewed as a revolution rather than a modernization of the good old VF700.
The new cooler is packed into a small cardboard box with a round window that gives you a view of the front side of the Zalman VF900-Cu LED:
The cooler is firmly fixed in a plastic tray; the accessories and manual are in the top of the box. Detailed information about the product’s technical characteristics is given on the reverse side of the package; small photographs illustrate the key points of the new cooling solution.
The cooler’s base, impressive with its flatness and mirror-like polish, peeps out through the small window.
The package contains the following components:
According to the text on the box, the cooler is manufactured in Taiwan.
The VF900-Cu LED consists of two copper heat pipes with a diameter of 5mm which go out of a copper base and curve along the cooler’s perimeter into a full circle.
There are as many as 160 thin copper plates (with a thickness of only 0.2-0.25mm) on the heat pipes. They have contact with the pipes not only with their ends but also through solder (you can see its traces in the photograph). The heatsink is cooled with a fan that has translucent 75mm blades and light blue highlighting.
The cooler’s fan is fastened with two screws to the top and with one more screw to the middle of the heatsink. A small pipe curves around the base of the fan. This is not a heat pipe, and it is made up of pressed-out ends of the thin plates.
As you can see, the cooler’s base is ideally polished and absolutely flat.
I unfastened the four screws in the cooler’s base to have a look under the bottom half where the heat pipes are located, but I couldn’t do so even though I found no more screws. I suppose there is some thermal glue (or even solder) between the two parts of the base and this prevented me from taking it apart.
The Zalman VF900-Cu LED is compatible with all modern (and not very modern) graphics cards. This is how the cooler’s compatibility is illustrated in the user manual:
The numbers next to the holes correspond to the list of graphics cards shown in the following table:
The list seems to be exhaustive, yet there is a graphics card that is missing there. It is the GeForce 7950 GX2 model (for details see our article called Two for One: Nvidia's Dual-Chip GeForce 7950 GX2 Reviewed) – it’s really hard to find a replacement to its standard cooling system.
It’s easy to install the Zalman VF900-Cu LED on a graphics card:
I think no additional comments are necessary here. You won’t need any tools to install your Zalman VF900-Cu LED. The fixing nuts are fastened with your own fingers through the spacers and springs.
You can download detailed installation instructions from the official website (a 1.09MB PDF file).
The characteristics of the new graphics card cooler from Zalman are listed in the following table in comparison with the last-generation Zalman VF700-Cu model:
You can notice that the maximum fan speed of the new cooler is considerably lower than that of its predecessor. It means the level of noise is lower, too. Besides the heatsink design, the Zalman VF900-Cu LED has the following advantages over the VF700-Cu model: a Fan Mate 2 speed controller included into the package, fan highlighting, and thickness (15mm against the VF700’s 10mm). Alas, these advantages come at a price, which is almost two times the price of the Zalman VF700-Cu.
We tested the Zalman VF900-Cu LED and its today’s opponents on the following testbed:
I tested the cooler on two graphics cards: 1) on a Radeon X800 GTO2 which has a moderate appetite by today’s standards, but I enabled 16 pixel pipelines in it and overclocked it a little above the default frequencies of the Radeon X850 XT PE, and 2) on a Radeon X1900 XTX which is unrivaled in terms of heat dissipation among today’s graphics cards. So, you will see if it makes sense to install the Zalman VF900-Cu LED on modern and high-power devices as well as on graphics cards with relatively low power consumption.
The tests were performed in Windows XP Professional Edition Service Pack 2. The ambient temperature remained at 25-25°C during the tests.
The unblocked and overclocked Radeon X800 GTO2 had to run the Firefly Forest test from 3DMark2006 for ten times without full-screen antialiasing but with 16x anisotropic filtering. The Radeon X1900 XTX was heated with the Deep Freeze test with the same settings. The temperatures were monitored through RivaTuner v2.0 RC16. Each cooler was tested at least two times, and the temperature stabilization time between the test cycles was 30-40 minutes.
I took the following coolers as opponents to the Zalman VF900-Cu LED in this test session:
The stock coolers were tested in two modes: when the fan speed was controlled automatically and when it was manually set at the maximum. The Zalman VF700-Cu was tested in the quiet mode (~1980rpm) and at maximum fan speed (~2820rpm). The Zalman VF900-Cu LED was tested in three modes: 1) silent or at min fan speed (~1320rpm), 2) quiet (~1980rpm) and 3) max fan speed (~2400).
First, you can take a look at the Zalman VF900-Cu LED installed on the Radeon X800 GTO2:
The new cooler from Zalman is almost the same height with the card, so it can blow at all the elements near the GPU as well as at all the memory chips.
And here are the results:
The difference between the coolers seems to be negligible at first sight: no bigger than 10.6°C between the worst and the best result. But take a look at the performance of the Zalman VF900-Cu LED in the silent mode: the new cooler on heat pipes is as effective at the minimum fan speed as the previous model VF700-Cu is at the maximum speed! This is a great success considering that the coolers are tested on a graphics card with moderate heat dissipation. If you increase the fan speed of the VF900-Cu to the quiet 1980rpm, you’ll reduce the GPU temperature by 2°C more. Increasing the fan speed to the maximum doesn’t bring any improvements in the cooling efficiency.
Perhaps the low heat dissipation of the unblocked and overclocked Radeon X800 GTO2 prevents the Zalman VF900-Cu LED from showing its full potential? Let’s check it out on a Radeon X1900 XTX.
The following photographs show the coolers installed on the Radeon X1900 XTX card:
Standard cooling system 
Zalman VF700-Cu 
Zalman VF900-Cu LED 
Va-Aqua (RL-VNC-CNU1) water-cooling unit 
Note that the Zalman VF700-Cu installs on the Radeon X1900 XTX in such a way that its fan covers almost all of the graphics memory chips whereas the Zalman VF900-Cu LED is installed somewhat higher and even goes beyond the top edge of the graphics card. The Va-Aqua water-block doesn’t cover anything other than the graphics core and doesn’t air-cool the PCB at all.
Here are the results of this test:
Well, there’s not much practical value in the results of the Radeon X1900 XTX’s stock cooler at its full speed. It does cool the GPU very well, but the noise from the plastic blower rotating at 5100rpm is just unbearable.
Comparing the other coolers, you may note again that the Zalman VF900-Cu LED cools the GPU as efficiently in the silent mode as the Zalman VF700-Cu at the maximum fan speed. And again there is not much improvement from increasing the fan speed of the new Zalman cooler. I should confess that the GPU temperature is still rather high despite the use of heat pipes in the VF900-Cu LED’s heatsink.
I think that the Aquagate liquid cooling system is the only cooler participating in this test that ensures comfortable conditions for the GPU of the Radeon X1900 XTX. It keeps the GPU temperature below 65°C (and I ran the 3DMark06 test for 25 rather than 10 times for this cooler since a liquid cooling system takes some time before the liquid warms up). You should be aware that the water-block cools the GPU only, but the memory chips and the PCB of the graphics card are not cooled because the Aquagate lacks a fan.
So, what about the PCB temperature? The readings of two temperature monitoring sensors of the Radeon X1900 XTX will help us see that.
It might have been expected that the temperature of the card in general and of its voltage regulator in particular is going to be high with the liquid cooling system due to the lack of any air stream to cool them. The high temperature with the new VF900-Cu LED is somewhat alarming. I guess it’s the position of the cooler (high up the card) that affected the temperature of the power circuit and the PCB. This is indirectly confirmed by the results of the Zalman VF700-Cu which easily wins these tests.
So, is the new Zalman cooler worse than the older model when it comes to cooling a top-end graphics card? Not quite. It’s the practical result that’s important, so I tried to overclock the Radeon X1900 XTX using both the Zalman coolers. And I found the Zalman VF900-Cu capable of keeping the Radeon X1900 XTX up and running at 680MHz GPU and 1630 memory frequencies (with a core voltage of 1.55V), even though the GPU temperature was as high as 98°C. With the Zalman VF700-Cu, the GPU clock rate of 670MHz was the maximum and the system would hang up if it was set higher (with or without a voltage increase). It looks like the cooling of the core is more important for the Radeon X1900 XTX than the cooling of the card’s PCB or voltage regulator. This may be different with other graphics card models, though.
A cute appearance, high efficiency, a very quiet fan with highlighting, tool-less installation on the graphics card are what the Zalman VF900-Cu LED cooler is. Added in its package are such nice accessories as a fan speed controller and thermal paste.
Highs:
Lows: