With all the great reviews Thermalright?s XP-90 and XP-120 heatsinks have gotten I expected slightly lower cpu temps after I installed the XP-90 with AS5 on my Athlon64 3200. With Cool?n?Quiet disabled my cpu temp at idle is 38 ? 40 C, full load 48 ? 50 C, case temp 30 - 31 C, ambient (room) temp 25 C , and cpu fan speed 2800 rpm. I am using Speedfan and Epox?s Thunderprobe to monitor temps.
I have reseated the heatsink a number of times following Artic Silver's instructions on how to apply it, but did not see any temp differences, nor have I seen any temp drops after the 200 hour AS5 "break-in" period.
With case temps of 30 -31 C I think my main problem is inadequate case cooling. I have 2 - 80mm fans blowing in, 1- 120mm fan blowing out, and 1 - 120mm fan on my psu blowing out. I may try adding another exhaust fan. This would give the case more negative pressure. While negative pressure is considered better than positive pressure for cooling it will also suck in more dirt.
There are some over at the Overclockers forum claiming that the bases of a lot of XP-90 and XP-120s are not flat but concave (lower in the middle) and need to be lapped.
OC Forum1
OC Forum2
OC Forum3
OC Forum4
OC Forum5
The pics show that as the heatsinks are lapped the nickel plating starts coming off the edges first. This would suggest that the heatsink base is concave. Someone though did make a good point in that the bases may be flat and the nickel plating is thicker in the middle than on the edges.
I emailed Thermalright and of course they said not to lap the base since it is nickel plated. The base consists of a quarter inch thick slab of copper with a nickel plating. The aluminum fins and heat pipes are soldered to the copper base. Copper has much better thermal conductivity than nickel, Thermal Properties of Metals, so why did Thermalright nickel plate the base. Was it to match the overall color and design of the heatsinks? Increase effective contact between the heatsink and the cpu? Help keep the heatsink together? There have not been any posts in the Overclockers forum of the heatsinks falling apart after being lapped.
I have not checked my XP-90 for flatness yet, but right out of the box it did have some deep scratches on it in the middle of the base. IMO, the easiest and cheapest method to check flatness is the one used by Galvanized Yankee. Place a straight machinist?s rule on the heatsink base. If the rule rocks or you can see light under it near the edges of the heatsink then it?s convex (higher in the middle). If you can see light under it in the middle then it?s concave. Another method suggested by someone over at Overclockers is to place a small dab of heatsink compound on the heatsink base, place it on a flat piece of glass, gently apply a small amount of downward pressure on it, and then check the pattern of the heatsink paste on the bottom side of the glass. If there is little or no spread of the heatsink paste then your heatsink is probably concave. If the heatsink is convex you may be able to easily rock it from side to side.
If you check your XP-90 or XP-120 and find it's not flat and want to lap it here's the best lapping instructions I have found and the kits prices are reasonable.
EasyPCKits
Lapping Instructions
I have reseated the heatsink a number of times following Artic Silver's instructions on how to apply it, but did not see any temp differences, nor have I seen any temp drops after the 200 hour AS5 "break-in" period.
With case temps of 30 -31 C I think my main problem is inadequate case cooling. I have 2 - 80mm fans blowing in, 1- 120mm fan blowing out, and 1 - 120mm fan on my psu blowing out. I may try adding another exhaust fan. This would give the case more negative pressure. While negative pressure is considered better than positive pressure for cooling it will also suck in more dirt.
There are some over at the Overclockers forum claiming that the bases of a lot of XP-90 and XP-120s are not flat but concave (lower in the middle) and need to be lapped.
OC Forum1
OC Forum2
OC Forum3
OC Forum4
OC Forum5
The pics show that as the heatsinks are lapped the nickel plating starts coming off the edges first. This would suggest that the heatsink base is concave. Someone though did make a good point in that the bases may be flat and the nickel plating is thicker in the middle than on the edges.
I emailed Thermalright and of course they said not to lap the base since it is nickel plated. The base consists of a quarter inch thick slab of copper with a nickel plating. The aluminum fins and heat pipes are soldered to the copper base. Copper has much better thermal conductivity than nickel, Thermal Properties of Metals, so why did Thermalright nickel plate the base. Was it to match the overall color and design of the heatsinks? Increase effective contact between the heatsink and the cpu? Help keep the heatsink together? There have not been any posts in the Overclockers forum of the heatsinks falling apart after being lapped.
I have not checked my XP-90 for flatness yet, but right out of the box it did have some deep scratches on it in the middle of the base. IMO, the easiest and cheapest method to check flatness is the one used by Galvanized Yankee. Place a straight machinist?s rule on the heatsink base. If the rule rocks or you can see light under it near the edges of the heatsink then it?s convex (higher in the middle). If you can see light under it in the middle then it?s concave. Another method suggested by someone over at Overclockers is to place a small dab of heatsink compound on the heatsink base, place it on a flat piece of glass, gently apply a small amount of downward pressure on it, and then check the pattern of the heatsink paste on the bottom side of the glass. If there is little or no spread of the heatsink paste then your heatsink is probably concave. If the heatsink is convex you may be able to easily rock it from side to side.
If you check your XP-90 or XP-120 and find it's not flat and want to lap it here's the best lapping instructions I have found and the kits prices are reasonable.
EasyPCKits
Lapping Instructions
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