I just went through all 79 of my processes on Windows Task Manager and changed them all to core 3, and sins to core 0, but that didn't help.  Before that I changed the priority to High and that also did nothing.  On my motherboards tuner program, my CPU is still showing spikes run up to 100% right after the freezes end, so you're right, my CPU is maxing out, but only for a few seconds.  Otherwise it's showing Core 0 running at 50-60% most of the time for Sins.

That's the thing.  I've played games much larger than the one I'm having these stutters in without problems.  This is just a 1v1.  I should also add, that it only started like 3 hours into the game, a few minutes after I began accelerating the gamespeed to x4.  It was fine before then, and our fleet sizes hadn't changed that much.

I'm playing with Distant Stars 1.0, and the only thing that's arguably rarely used that I was building was lots of Kol Battleships.  Nobody uses those, lol.

This can be your problem... you have overclock your processor... normal frequency for these processor is 3.3 ghz... Intel say that it remain stable to the max frequency of 3.7 ghz ( turbo mode is for short time only )... some people with liquid nitrogen cooling have push it to 5 ghz without loosing stability but i doubt that you have a similar cooling installation...

I have doubt that Stardock will give support to somebody who push his hardware over the recommended limit...

my CPU is still showing spikes run up to 100% right after the freezes end, so you're right, my CPU is maxing out, but only for a few seconds.

Well, in case of overcloking, error can happen, a lot of them can be corrected by flushing the threat pipe and start the process... in case of my own processor, a pipe is 26 step... mean that you need time for the flushing and reload... a lot of clock cycle...

If error cannot be corrected, it simply crash... have not happen for me in year but i know that in some case, mainly with 3D render who use a lot of resource, there was error since they are in a log of my bios... well, i have 1, 4 and 8 bits correction along with RAM mounted like a raid system ( 16 gb physical but only 8 gb can be use )... and if a core become too much hot, the treat jump in a automatic way to a other core in the other processor...

By the way, i don't think that the cpu at 100% is a game problem, maybe a OS problem like the 2gb limit... look at the screenshot below :

Game is using 6% of my processor power, since i have 2 xeon with quadcore, it is like 48% of one single core... and i have a lower frequency that you, at 2.66 ghz... was playing with the biggest mod for sins, with 10 different races on a custom map with 20 star and over 350 planet... with some personal tuning who allow me to have 128 starbase in a gravity wheel and a lot more capitalship/cruiser/frigate...

Only difference is that i don't use a Microsoft OS...

By the way, look at the memory use... over the so called "2gb limit" with a non modified sins.exe ... when modified for large address aware, i have push it over the 11.5 gb memory use before crash... 

SHORT VERSION : stop overcloking, drop your processor frequency to his normal value ( 3.3 ghz ) and try again...

It is a Bios option...

Supermicro X7DA3+ manual page 4-12

Advanced chipset control > Memory branch mode > the option are interleave, sequential, mirroring and single channel

Mirror mode allow data correction by maintaining two copies of data in two branches.

You can only change defective ram without shutdown the computer when you are already in mirror mode...

Well, when i have setup my computer, i have use a computer like yours ( MAC Pro ) for model but i have push it a level more... motherboard is a professional server board... plenty of bios option work work only for Unix ( and Linux )... majority of them are for stability and reliability... same my bios is duplicate with a backup... two time 8 mb...

Well, it is great for game too... by example, i have a bios option called "discrete MTTR Allocation" who speed up memory transfer to the graphic card in system with more that 4gb main memory... since your computer is more new that mine, it is maybe called PAT ( Page attribute table ) in your bios ... it is the same that MTTR but a lot more flexible... normally, it work for OS X, Unix, Solaris, Linux, and more... but not on windows...

Well, i have no merit, i have study it when i was working at the army... no true, it was Unix... but Linux is somehow a clone of Unix... and i have plenty of year of experience...

Today linux version are really easy to use, like windows... but like windows, you don't have top performance by just installing a distribution... i compile my own kernel, my own wine version, etc... 

Since the topic is about sins performance, let use it for example... when fevs make a game, they need to be sure that it work with every possible hardware and configuration... this greatly complicate and inflate the code generated... if source was deliver in place of binary, at compilation configaration, you can discart everything who is not related to your own hardware... mean a more compact and faster binary... but it mean that the bin will only work on your computer and that if you change your hardware, you need to recompile the application... it sound like a DRM thing but in this case, it is about performance...

Maybe, with digital purchase of game, a new way of increasing game performance can be created... before download a game, the store software will check your hardware and compile in real time a .exe who will be fully optimized for your computer... it will increase greatly the game performance and reduce piracy in the same time ( since the optimized game exe will only on a computer fully identical to yours )... if you buy a new computer or change some hardware piece, loggin and create a new .exe ... since games exe are small, it will not use a lot of internet band for download a new version... Sure it is a crazy idea, i already see the comment about private life, not wishing that a externe software check your hardware for better performance...

EDIT : almost forget, if you look again the pic in my previous post, you can see that sins use 3% of one processors and 3% of the other... so, in fact, in my case, sins use two thread, one on each processor, it use 2 core at 18% each... it is only possible on multi processor motherboard using a method called speculative multithreading... Only useful for application who was no compiled with the optimization called automatic parallelization who allow to convert sequential code in multithreaded or vectorized code ( work only on multicore who share the same memory )...

EDIT2 : Oppsss... to much off topic... sorry ...

Now that i see the Major Stress post, i have one question for Manick... what version of sins do you play... Vanilla, Entrenchment, or Diplomacy...

If it is one of the first two, it is a good idea to use the TSOP mod... it smooth the game... with diplomacy, it is not so much needed since several of the TSOP fix along with some Stardock optimization was included in one of the last few patch... so, be sure that your have a updated version of sins/ent/dip...

As for the so called 2gb limit, i don't think that he hit these barrier because he have only 4 gb ram... With 64-bit editions of Windows, only 32-bit applications marked with the IMAGE_FILE_LARGE_ADDRESS_AWARE flag have the full 4gb ram via wow64... problem is that he have only 4gb and sins is not with the large address aware...  result is the well know 2gb OS thing and 2gb for ALL application... let say, that he have some software running in the background like antivirus, steam or impulse, chat software, etc ... and it will remain less that 2gb for sins...

In xp you can add the /3gb to your boot.ini for make a 1gb OS and 3 gb for ALL application... with win server 2003, it is the the boot userva switch at 3072... Vista is with BCDedit /set for set the boot option increaseuserva to 3072... for win7, i don't know, Vista flop have make me fall back on my good old Win Xp pro x64 and i have not yet feel the need of a more colorful desktop with rounded windows corner who eat a lot of resource...

A other thing, sins cache everything ( very few files have the  loadondemand tag ) in ram for speed up the game... if you have not yet reach the 2gb limit for sins but have already hit the 2gb limit for ALL apllication together, that you have virtual memory enable, the OS will begin use the harddrive like a cache for the ram... this can cause the stutter... check if your HD led flash when these stutter thing happen...

Wrll, i use gcc, the open source compiler... a good one but not the best... cannot compare with the top quality commercial compiler who have plenty of option...

Any way, recompiling a single thread application with the option automatic parallelization lead at least to around 7% performance increase... it is a little but it is better that nothing...  Without any rewrite of the code, AP option mainly use parallelism for the loop...

As for performance, there is a other way possible but gamers will hate it more... having the application running on a dedicated server... somehow, a fall back to a old technology... was in use at my previous work... a powerful local server with application and local terminal in each office...

Well, there is some potential for performance in the future... by example, opencl is now supported by more big brand like nvidia, AMD, Intel, etc... opencl allow to use the power of GPU/CPu or any processor... somehow a follow up of the NV CUDA or the AMD "close to metal"... So, there is a lot of hope for a increase in performance in a sins 2...

As for actual sins and the use of a second thread, if i good remember, it happen during load time... some of the last sins optimization have not be fully included in previous engine... now, diplomacy have more content and run smoothly that sins/ent... As for Rebellion, devs have speak of more optimization was make who lead to a game running more smoothly...

I have know plenty of freezes myself but mainly when i was trying to push the iron engine  at his limit... by example, have slow down when i have more that 20 million poly on screen in sins but i think that it is more a graphic card limit ( nv 9600 GT )... have slowndown when i have more that 250 mobile starbase in a gravity wheel mainly due to not enough room in the gravity wheel and the collision detection thing... have slowdown with mod who greatly increase the amount of fighter... have slow down a few weeks in the game when i use monster map ( 20 star and more that 350 planet with 10 races )...

Well, i have sometime, rarely, slowdown in normal game too... the cause is simple, sins is a true real time game... some of the so called real time game freeze the time at the strategic level when a battle happen ( tactical level )... when battle happen off screen ( two AI by example ), they use some autoresolve simplified algorithm... with sins, time don't freezr in the galaxy when you start a space battle... more, you maybe start a little battle but it is possible to somewhere else in the galaxy, there is a huge battle between several AI... since the game is really real time, there is no autoresolve for AI fight... fight need to happen like a real fight... it take time and computer resource...

This game have a huge potential for the future with more recent technology... just hope that they don't follow the actual trend of sequel who remove feature for make the game more simple... With Rebellion release on Steam, the game will attract a amount of new player who are not used to deep complex strategy game... there will be complain that the game is too complex... hope that devs will not listen to these complain and make a over simplified sins II...

Almost a week and a half later and I still haven't experienced the same problem again.  Something must have just bugged that particular save file, either by something I did, or from the mod I was using.