Performance

After the initial installation the heatsink was immediately removed and the contact area was inspected. Heatsink contact is just "wow". On the core there is almost no thermal paste left, on the cooler base you can make out the ATI logo.

After cleaning up the cooler base you can see that the mounting pressure is pretty high. There is a relief of the ATI logo imprinted into the copper:

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For the overclocking tests I used my ATITool overclocking utility version 0.0.24 Beta 9. ATITool has the unique ability to detect artifacts, or flaws, in a rendered image. As defined by ATITool, the maximum stable overclock on a card is the speed at which it is able to consistently (15 minutes in this test) produce no errors, or artifacts. ATITool detects ANY artifacts, even ones which will not be visible in game. Using the human eye to detect artifacts introduces subjectivity into the test, so despite the fact that an ATITool tested overclock will be characteristically lower than a human one, I will use this.

Temperature was measured with one case side open by b reading the on-die X800 XT thermal diode. Idle temperature was measured after letting Windows sit one hour at the desktop. Load temperature was measured after running 3DMark2001 looped for one hour. Both at the card's default clock of 500 / 500 Mhz.

Arctic Silver Lumière was used as thermal interface material for the GPU core in all installations. Lumière is a specially engineered testing compound - it needs no settle in time to reach its maximum performance, but it's not designed for permanent use.

A 7V setting is possible by connecting the fan connector's black wire to the PSU's 5V output, and the fan connector's red wire to the PSU's 12V output (12V - 5V = 7 V).

The dynamic fan setting of the card changes fan speeds from 43% (idle) up to 80% (load). The stock cooler was also tested with forced 100% fan speed for better comparison.




When looking at the data, the first thing you notice, is that even though load temperatures are considerably lower compared to the stock cooler, the maximum core clocks are actually lower (look at stock 100% vs. JACSH1 12V).
To make sure this is not an installation or measurement error, I tested stock cooler and JACSH1, three times each. Install JACSH1, install stock cooler, install JACSH1 and so on. The results are what you see above.

At the moment I do not have a perfect explanation for you, why this is happening, my guess is that the maximum core clock also depends on how fast the heat is removed from the core, not only the temperature.

While temperatures are pretty good, the overclocks are not existant, compared to the stock cooler. What the JACSH1 gives you, is a decreased sound level and lower temperatures at same clock speeds like the stock cooler.

A big disadvantage is, that the fan is not connected to the video card's fan power connector. This means that on cards which support dynamic fan controls, like all X800s, you will not be able to use that feature and your fan will constantly run at the same speed. Also the extra cable with the bulky connector is a bit disturbing for people who like to show off their case insides.

Value and Conclusion