|
AMD Phenom II TWKR Black Edition |
|
|
|
Written by Vladimir Dimitrijevic
|
|
Tuesday, 01 September 2009 |
|
Page 1 of 3   Term “tweaking” is closely connected to some sort of electronic device and represent minute modifications in hardware which results in better performances. When it comes to overclocking, tweaking as term is used a lot. When it comes to competitive overclocking tweaking means anything that results in better results in HWBot. The more tweaks you know higher are the chances of better result or even world record.
| Cold Bug Problem |
Cold bug is problem that occurs only during extreme overclock. Cold bug happens when you cool down CPU at temperatures below zero at which CPU stops to operate correctly. It’s not dead just stop working properly. At the beginning of the overclocking era that wasn’t a big problem but after some time when dry ice (liquid carbon dioxide) or liquid nitrogen begun to be used as cooling agent for extreme overclock this problem stated to occur more often. CPU manufacturers also started to pay attention at this problem as race for fastest CPU was gaining momentum. To explain what happens and how cold bug can be reproduced and avoided we will use an example. Intel E8600 CPU has cold bug around -150 degrees Celsius. This means that if you use dry ice that has minimum temperature of -78.5 degrees Celsius you will never reach its cold bug limit. However, no matter how low -78.5 degrees Celsius sounds low it is not enough anymore when it comes to reaching world records in overclock. More efficient cooling agent is liquid nitrogen that has lowest temperature of -196 degrees Celsius. So, if our Intel E8600 with cold bug at -150 degree Celsius reaches that value it will stop working. So it is obvious that for maximum frequency you need to achieve -149 degrees Celsius and what is more important maintain same temperature during all benchmarks. So it looks something like this. You have chilled your E8600 at -149 degrees Celsius, and you start 3DMark 05. CPU starts to warm up to -127 degrees Celsius and you start to add liquid nitrogen in the pot (cooler – explained in separate section) to lower temperature at -149 degrees Celsius so CPU can finish test. 3DMark 05 displays results, you take a screenshot but at that moment screen locks and you are not able to save a screenshot. What happened? When benchmark finished load on CPU has drop and it started to cool down but you added too much liquid nitrogen and now temperature dropped below -150 degrees Celsius and you reached cold bug.
How to prevent cold bug upon benchmark finished? There are many solutions to this problem: hardware and software. For instance you can use a blow drier to control temperature of the pot in which case condensation is real problem, and water and electric equipment doesn’t mach. Software solution can be SPi Tweaker. |
When it comes to competitive CPU overclocking Intel has dominated in almost all areas while AMD had significant problems in that segment. More so AMD has serious problems with cold bug which at one moment become a synonym for AMD CPUs although cold bug was also present on Intel CPUs. With introduction of Phenom II CPUs AMD finally made much needed step forward when it comes to extreme overclock and started to scale similar to Intel CPUs: lower temperature = higher frequency = better overclock result. Unexpected feature of new Phenom II CPUs was absence of cold bug even in cases when liquid helium was used when temperature of -268 degrees Celsius can be reached (very close to absolute zero = -273 degrees Celsius). Lack of cold bug turned completely new page for overclocking results and finally Intel and AMD can have fair competition.
6GHz and Higher
When it comes to competitive overclocking of AMD CPUs completely new era started with introduction of Phenom II 955 model that reached more than 6GHz at liquid nitrogen. Overclockers that used liquid helium reached even 6.4Ghz. Of course these frequencies resulted with high benchmark results.
For the first time in its history AMD made a CPU that didn’t have cold bug. This CPU is made from the start for maximum overclocking results and specially tweaked in AMD laboratories to it can reach very high frequencies. This CPU cannot be bought. AMD will give one of 100 of this CPUs to overclocking teams and each CPU is marked with its identification number and an “Not for Sale” inscription. Of course we are talking about AMD TWKR CPU.
|
