Unreal Tournament 3, Windows 7... IO spikes

[sloperb]

Here's my problem. While running Unreal Tournment 3 on Windows 7 under Parallels 5 on my iMac, the IO spikes to near 100% writes all the time. This is happening even when the game is paused. As soon as I stop the game, the disk stop spinning.

I have 4GB of RAM allocated to Windows 7 and 4.8GB fixed allocation to Parallels (fixed, not dynamic). Windows process monitor shows UT3 is only using about 480MB, so I shouldn't be swapping. I turned off all Parallels/Mac sharing features. I added the Documents/Parallels to the "private" list in Spotlight so it won't get indexed. I can't seem to find a way to figure out which processes are causing the IO to rule out a Mac process causing IO when UT3 is running, but watching Activity Monitor there isn't anything unusual going on there.

I have tried with 1, 4, 8 processors allocated to Parallels and so far found 1 processor is best.

Any ideas what to try next?

--sloperb

Here are my system specs:

27" iMac
2.8GHz quad-core Intel Core i7 processor with 8MB shared L3 cache; Turbo Boost dynamic performance up to 3.46GHz; Hyper-Threading for up to eight virtual cores
ATI Radeon HD 4850 graphics processor with 512MB of GDDR3 memory
8GB RAM

I'm running Parallels Desktop 5
Windows 7 Enterprise (64-bit)
Unreal Tournament 3

 

[sloperb]

I ran fs_usage to capture disk usage during this period where write IO was spiking while playing UT3 to see if I could find the culprit. Then I filtered write activity and sorted by number of writes. Here's what I got:

$ cat fs_output.log | grep write | cut -c153-200 | sort | uniq -c | sort -r -n

1467 prl_vm_app
746 mds
214 firefox-bin
156 Activity Monitor
104 activitymonitord
90 Terminal
55 bash
48 smbd
36 syslogd
33 prl_naptd
30 ls
26 smbclient
12 WindowServer
4 prl_client_app
2 nmblookup
2 aosnotifyd
1 nmbd
1 launchd

 

[sloperb]

I have identified the source of the problem. I used Process Explorer in Windows 7 and found that the writes were happening from the audiodg.exe file in Windows 7. I disabled the sound driver and now I no longer get the IO thrashing. In fact, I can run full-resolution (~2400x1500) in my iMac on low-res textures and don't get much skipping.

Downside is I no longer have any audio... hmm... Anyone have any suggestions here?