Win32 CPU Cycles vs 'Live Protection' Engines ?

I wanted to document an issue I encountered when first installing and using the Bitcoin software.

Despite a correct installation and port forward settings I noticed that Bitcoin was not generating any coins or ‘blocks’ despite having 20+ connections for the first 24hrs. The block count just remained at 0. After realizing that Bitcoin was not ‘catching up’ with the collective network block download or generation I opened up the Task Manager to investigate the issue further.

I noticed that the bitcoin.exe process seemed to be ‘fighting’ for CPU usage against MsMpEng.exe (Microsoft Security Essentials). I hadn’t noticed any system slowdown due to having a fairly high spec. PC. After adding bitcoin.exe and the appropriate program folder locations to Exclude ‘Files and Locations’ and ‘Exclude Processes’ - Bitcoin instantly started generating blocks and the CPU processes returned to normal.

I did not have any virus alerts or even ‘false positive’ identifications for Bitcoin. I know that the software is 100% OK. I’m assuming that the ‘Live Protection’ engine in Microsoft Security Essentials just doesn’t ‘play well’ with some aspect of the CPU hungry cycles used in ‘block’ generation.

I have yet to do more testing, however I also encountered the same issue when using Comodo Internet Security (free version).

This is obviously going to be an issue for lots of new Bitcoin users who will perhaps be less ‘tech savvy’. Has anyone else encountered any similar issues ?

Thanks for that.  Which version of Windows?

Windows XP - Home and Pro

I confirm this is a problem on Vista Ultimate as well.

The software seems to work, but blocks are being downloaded at an extremely low rate (several thousand for over ten hours), and the process MsMpEng.exe, running under the SYSTEM account, described as ‘AntiMalware Service Executable’, part of Microsoft Security Essentials, is constantly consuming no less than 50% CPU time, which along with bitcoin bring the system to 100% CPU utilization (no significant slowdown is perceived though). After I added bitcoin.exe to the “Excluded processes” list of Microsoft Security Essentials settings, everything went to normal.

System Specs: Windows Vista Ultimate (32-bit), AMD Athlon 64 X2 Dual Core Processor 5600+ 2.79GHz, 2GB RAM

Regards, Dimitri

Excellent tip. Just applied this fix to two very different computers, both running different versions of Windows 7 (64 bit). Looks to me like this is a universal issue (at least in the case of Microsoft Security Essentials virus protection).