Testbed and Methods
We tested the new cooling system from Scythe and its competitor inside a closed system case. Our testbed was identical for all coolers throughout the test session and featured the following configuration:
- Mainboard: ASUS P6T Deluxe (Intel X58 Express), LGA 1366, BIOS 1303;
- Processor: Intel Core i7-920, 2.67GHz, 1.25V, 4 x 256KB L2, 8MB L3 (Bloomfield, C0);
- Thermal interface: Arctic Silver 5;
- Graphics card: ZOTAC GeForce GTX 260 AMP2! Edition 896MB, 648/1404/2108MHz (1030RPM);
- Memory: DDR3 3 x 1GB Corsair DOMINATOR TWIN3X2048-1800C7DFIN (Spec: 1800MHz / 7-7-7-20 / 2.0V);
- Disk subsystem: Western Digital VelociRaptor (SATA-II, 300GB storage capacity, 10,000RPM, 16MB cache, NCQ);
- HDD silencer and cooler: Scythe Quiet Drive 3.5”;
- Optical drive: Samsung SH-S183L;
- System case: Antec Twelve Hundred (default 120mm fans replaced with Scythe Slip Stream 120 fans at 800RPM; 120-mm Scythe Gentle Typhoon at 800RPM installed on the lower front of the case; standard 200-mm fan at 400RPM at the top of the case);
- Control and monitoring panel: Zalman ZM-MFC2;
- Power supply: Zalman ZM1000-HP 1000W (with a default 140 mm fan).
All tests were performed under Windows Vista Ultimate Edition x86 SP1. We used the following software during our test session:
- Real Temp 3.19b – to monitor the processor core temperature;
- Linpack 32-bit with LinX shell version 0.5.8 – to create maximum CPU load (two test cycles, 15 Linpack runs in each cycle with 1624 MB RAM capacity involved);
- RivaTuner 2.24 – to visually control temperature changes (with RTCore plugin).
So, the complete screenshot during the test session looks as follows:
The stabilization period for the CPU temperature between the two test cycles was about 10 minutes. We took the maximum temperature of the hottest processor core of the four for the results charts. The ambient temperature was checked next to the system case or open testbed with an electronic thermometer with 0.1°C precision that allows monitoring the temperature changes over the past 6 hours. During our test session room temperature stayed at 23.5-24°C.
The noise level of each cooler was measured after 1:00AM in a closed room about 20sq.m big using CENTER-321 electronic noise meter. The measurements were taken at 1m and 3m distance from the closed system case. During the acoustics tests all five 120-mm case fans were slowed down to ~520 RPM. In this mode the background noise from the system case measured at 1m distance didn’t exceed ~33.3 dBA. When the system was completely powered off, our noise meter detected 30.8 dBA (the lowest on the charts is 30 dBA). The subjectively comfortable noise level is around 34.5~35 dBA.
Now let me say a few words about the today’s main competitors for Scythe Kabuto. First, we decided to include the Thermalright SI-128 SE top-cooler that didn’t participate in the recent super-cooler shoot-out, but definitely deserves being treated as such. Since SI-128 SE is incompatible with LGA1366 mainboards, we used the retention from IFX-14. Second, we also included the results for Thermalright IFX-14, which is the most efficient cooler today and will be used as a reference point for the sake of comparison.
Thermalright SI-128 SE and IFX-14 coolers were equipped with one and two SilenX iXtrema Pro IXP-76-14/16 fans 120 x 120 x 38mm in size. They were working at 930RPM and 1410RPM. We tested Scythe Kabuto with exact same fan, too. Thermalright SI-128 SE was also tested with the PWM fan from Scythe Kabuto cooler.
You may wonder what about the Mugen 2? Unfortunately, we couldn’t use the cooler with the best efficiency-to-price ratio as a reference this time. The thing is that installing Mugen 2 onto an LGA1366 mainboard requires removing the standard backplate and processor retention plate, which in its turn calls for taking the CPU out of its socket. Since we test a lot of coolers in our labs, we often remove the CPU from the socket. Of course, it has certain negative effect on the life span of the socket contact pins (I have already bent one of them, but fixed it). A regular user who replaces the cooler once every year and a half or even more than that, can easily install and remove Mugen 2 without threatening to damage the mainboard PCB. As for me, I can’t do that too often. Moreover, the backplate from the MUgen 2 retention kit is not designed for multiple installations, because its retention loops get pressed against the mainboard PCB which lowers the pressure on the cooler. Therefore, you may need to put additional washers beneath them eventually. I believe the reasons described above are sufficient to justify the replacement of our reference cooler with Thermalright IFX-14.