Have the same issue. Windows 7 pro x64. AMD.
The regular "flush idle memory" command like this one didnt help:
%windir%\system32\rundll32.exe advapi32.dll,ProcessIdleTasks
But with applications like "smart ram" i could free up all memory and prospond the freeze.

I uploaded my stuff to the ticket (DayZ.rar) incl:
DayZ.RPT
DayZ.bidmp
DayZ.mdmp
DayZ.cfg

you can also download it from my domain:
http://tinyurl.com/lr4h38s

i7-3820@3.6 ghz. win7 pro x64 (7601). 16gig 1600hz cl7 memory.amd 7980 and 2x soundcards Creative X-FI titanium. Ingame settings: all medium, blur/bloom/headbob=off, static number set on gpu memory (2gig, even tho my card has 4gig, same issue if 'default' is used). . Issue occours anywhere on the map, ive managed to move from elektro to the new town in north, every 10-15min everything freezes and i need to ctrl-alt-delete and close dayz process. Nothing specificly happens cept that gpu goes idle just before the freeze. Ive tried thirdparty memoryflush for gpu and regular memory - same issue (just slightly delayed). Adding the GPUrenderahead= to '3' in cfg helped alittle with the fps, but the freeze still occur.
edit: Dosent matter if its day-night, sunny or rainy - same issue
edit2: last crash occured at the cargoship. 1920x1080 resolution, amd driver package 13.9

To add some more information:
I droped everything i had, relogged to other server = still freezing.
I killed myself to get a new fresh char = still freezing.
I tried same on both hardcore and regular = still freezing.

on another mosin ticket it says lightfoot have resolved this, its still the same for me in stable.

^
in the specific ticket there is no info that it will be "next patch" when i wrote my comment. the ticket is just put as "resolved" with no futher information, its now added tho but this ticket was for v.4500.