by Tim Tscheblockov
10/28/2004 | 04:34 PM
We have already reviewed power supply units (see our 3 Zalman Power Supply Units Roundup), unique PC cases (see our 25 Kilograms of Silence: Zalman TNN500A Case Review) and water cooling solutions (see our article called Aesthetic Water Cooling Solutions: Zalman Reserator 1, ZM-WB2 Gold and ZM-GWB1). Today we would like to intorduce to you one more interesting product: the ZM80D-HP fanless VGA cooler.
All ZMxx series cooling systems from Zalman share the same basic design: an aluminum block is fastened to the graphics processor to take its heat and transfer it to a big passive radiator. This heatsink is but slightly smaller than the graphics card itself, while its ribbed surface has a total area no smaller than that of a standard heatsink. To improve the cooling, Zalman’s systems use two passive heatsinks, rather than one. The second is located at the back side of the graphics card and absorbs heat from the GPU via a heat pipe.
The ZM80D-HP is distinguishable from all the previous models for its using two heat pipes rather than one. This facilitates heat transfer from the GPU and face-side heatsink to the backside heatsink – the overall efficiency of the system is thus improved.
The ZM80D-HP kit is packaged into transparent plastic – for the whole world to see:
We have two heat pipes, two large heatsinks, eight heatsinks for memory chips, two GPU blocks, a screwdriver, and a pack of fasteners which is hidden under the picture to the left of the big heatsinks.
A pack of spare fasteners, in case you lose a screw or nut, and exclusive thermal grease from Zalman are enclosed with the ZM80D-HP.
We have everything necessary to put the system together – let’s try to do that.
To check out the ZM80D-HP under the harshest conditions, I used one of the hottest graphics cards of today, a RADEON X800 XT from Sapphire.
The device is based on the ATI RADEON X800 XT graphics processor and has 256MB of Samsung’s GDDR3 memory on board. The regular frequencies of the card are 500/500MHz.
Note that the memory chips have no cooling at all on the card. Well, the chips on the face side enjoy a refreshing breeze from the GPU cooler, but those on the backside are left on their own.
That’s why I didn’t use the memory heatsinks from the ZM80D-HP kit: if people from ATI think they can leave the memory chips without cooling, I will do the same. Anyway, the memory heatsinks won’t be without use: you can put them on the power elements of your mainboard or give to your friend-overclocker whose card works at increased frequencies or has hotter memory chips than GDDR3.
But let’s continue with the assembly. First of all, you choose the right block to mount on the graphics processor. ATI’s RADEON 9500/9700/9800/X800 series chips have a protective frame that prevents the core from chipping, so you should select the smaller block from the ZM80D-HP kit. The sole of this block is profiled in such a way as to provide a normal contact with the GPU even when the frame is above the die.
Before mounting the block on the GPU, you must get rid of the standard cooling system and make sure there are mounting holes on the PCB around the graphics core.
Graphics cards of NVIDIA’s GeForce 6 series consume somewhat more power and generate more heat than ATI’s RADEON X800 XT chip (see our article called Power Consumption of Contemporary Graphics Accelerators. Part II: NVIDIA vs. ATI), but they don’t have such mounting holes, so you cannot use the ZM80D-HP with them. RADEON X800 series cards, on the contrary, have such mounting holes near the graphics core and allow installing the passive-cooling system without any troubles.
Following the installation guide you receive with the ZM80D-HP you should perform the assembly easily enough. Just don’t forget to apply some thermal grease to where the heat pipes contact the heatsinks and the GPU block.
Zalman recommends that you attach an insulating sticker to the sole of the base against the graphics core on the back side of the PCB. However, it was hardly necessary with my RADEON X800 XT as the next snapshot shows that the base is 2-3 millimeters above the PCB.
This snapshot shows you the profile of the block’s sole that takes heat off the graphics processor. You can also see that the frame around the die doesn’t prevent a proper contact.
So, the system is complete. The configuration of the system and the dimensions of the heatsinks are selected such as to minimize any problems when it comes to installing the graphics card with the ZM80D-HP on mainboards. Anyway, you have to say good bye to the adjacent PCI slot: the heatsinks of the ZM80D-HP are rather far off the card’s PCB to avoid contact with capacitors and other tall elements of the graphics card’s surface.
I laid the heatsinks down on the memory chips to make this snapshot – to show you a fully assembled system. I remind you once again that I didn’t use the memory heatsinks in my tests.
Now, the graphics card and the ZM80D-HP system are ready for my testing, I only want to make one final warning: having mounted the ZM80D-HP system on the graphics card, try to install the card into the AGP slot without touching its heatsinks. Otherwise, this entire contraption of heatsinks and heat pipes may turn around on the graphics processor, decreasing the efficiency of cooling. So, manipulate the card touching the edges of its PCB only.
I tested the Sapphire RADEON X800 XT graphics card with the ZM80D-HP cooling system from Zalman in an Ascott 6AR system case that has two low-speed 120mm fans (one is taking air in, the other – out).
The testbed was configured as follows:
There were two test modes: Idle (no running applications; Windows’ Desktop onscreen) and Burn (3DMark05’s gaming tests were looped in 1024x768 resolution, with 4x full-screen antialiasing and 16x anisotropic filtering).
The temperature data were measured after an hour and a half of the system’s being in each of the test modes. To read the temperature of the GPU (“Core”) and the surface of the graphics card’s PCB (“Ambient”) I used RivaTuner. This utility can read data from the thermodes of the RADEON X800 XT, one of which is located in the GPU die and another is built into the monitoring chip found on the face side of the PCB near the GPU voltage regulator. I also measured the temperature of the graphics memory chips and of the air inside the system case using a Fluke54-II thermometer with its sensors (one of the sensors is shown in the photo below – it’s pressed to the surface of a memory chip):
The second sensor was placed one centimeter above the bottom of the system case.
First of all, let’s view the results of the Sapphire RADEON X800 XT wearing its standard cooling system:
Quite naturally, the temperatures are all right in the Idle mode. The card is practically noiseless, too, as the standard cooler is working at about 60% of its maximum speed when the GPU load is low.
In the Burn mode, however, the temperatures of the graphics processor and the memory chips grow up to 60-70°C. This is high, although not deadly. The fan accelerates to its maximum rpm rate in this mode, making quite an annoying sound.
Now, the same test, but with the Zalman ZM80D-HP installed:
The results suggest that the ZM80D-HP is worse than the stock cooling system as concerns cooling the RADEON X800 XT graphics card. The temperatures are slightly higher in the Idle mode compared to the first test, and quite dangerous in the Burn mode: your graphics processor and memory won’t last long working at 80-90°C.
Still, it’s too early to claim a failure of the ZM80D-HP. It is just not intended to work with graphics cards of the RADEON X800 XT class without additional cooling. Zalman highly recommends that you use an additional air cooler when installing the ZM80D-HP on graphics cards like NVIDIA GeForce FX 5800 and ATI RADEON 9800 PRO and faster. The company recommends that you purchase a ZM-OP1 cooler for that purpose.
I didn’t have a ZM-OP1 at hand during my tests, so I just took a low-speed 80mm fan, lowering its voltage from 12v to 7v.
That’s quite another story! With a little help from the additional low-speed fan, the ZM80D-HP easily beats the stock cooler in terms of efficiency as well as noise (the additional fan is not audible at all, while the standard cooler is wailing perceptibly under a load).
The ZM80D-HP shows itself as a worthy replacement to the standard cooling system of a graphics card of the RADEON X800 XT class. When used with an additional fan, it is better than the standard in terms of efficiency as well as of acoustic comfort. Of course, the use of the additional fan is not quite “fair play”, even if it’s completely noiseless, but without it the temperatures of the GPU and memory on the RADEON X800 XT card would be dangerously high. Well, Zalman itself not just recommends but insists that you install an additional fan when using the ZM80D-HP with so powerful graphics cards.
So, here’s the list of the ZM80D-HP’s highs: