I ran task manager on my 2nd monitor while playing Bioshock to see how it would use my qx6850. Overall processor use sat around 45% - 50%. The 4th core was very busy, running almost constantly at full capacity, the other cores didn't work very hard.

Is this game just not made for multiple cores? Or am I seeing this 50% CPU use because the game is designed specifically for 2 cores? (and thus using about half of my cpu's power)

The current bottleneck in my system is the memory (the FSB is actually capped badly right now, at 333mhz, 1333mhz capable). It's temporary ram, and I'm expecting some 1200mhz kingston stuff to come in pretty soon. Would the poor ram be the cause of this?

Bioshock simply doesn't take advantage of your QX6850.

Ram isnt the prob dood.

Remember... the fsb is QUAD pumped, while the ram is DOUBLE pumped
So....
ur fsb would be 1333/4=333.3
ram (for example) 667/2= 333.3

This gives the perfect 1:1 ratio, and u DONT NEED faster ram unless you plan to OC

800Mhz ram: 800/2=400
Therefore you could run 400x4=1600 FSB in 1:1
Assuming ur cpu/cooling/mobo can handle it.

Your 1200Mhz ram = 600mhz
Running 1:1 this would give u a new fsb of 2400Mhz Ie: Impossible

Even on a very nice OC, anythinh much over 800Mhz ram is a waste

Yep. It seems Bioshock isn't designed for more than 2 core.

Oh well. At least you'll be prepared for games that will take advantage of quad core in the future.

I haven't tried the BioShock demo (or full game) yet, so I am not the best person to say, but it's possible that your CPU is just "too" powerful for the game.

From what I have been hearing, BioShock seems to be running extremely on even modest setups. A QX6850 should have absolutely no need to run at 100% in this game. BioShock probably uses coarse multi-threading (I think that's what it's called). This is where different segments of the game engine run on separate cores i.e. A.I. one, Physics on another and so on, as opposed to fine multi-threading, where the entire workload is split evenly among available cores.

Considering all XBOX 360 games use the coarse multi-threading model, except the upcoming HL2 Ep2 - AFAIK (Valve got special permission from Microsoft for that), it's very likely that the same threading model was carried over to the PC as well. It's not the most elegant threading model, but one that's fairly easy to implement, compared to the alternatives.

So BioShock may very well be multi-core aware, and using your Quad to the best of its ability. The last core may be handling the game engine misc tasks, or physics, or maybe only water simulation , and is therefore working away at max, while the other cores don't have anything to max them out all the time, like AI etc.

Thanks for the update.

Mrmez thanks for the advice as well. I'll be sending that ram back where it came from and stick with my current setup, since as you say it's running fine with what I have.

Live and learn ^_^

I think we'll see this behaviour a lot in the future. That is, one core at 100% and the other 3 at various levels between 0 and 100. A game is not like a video encoding program, you can't split it into 4 threads that do the same thing. In a game you'll have a thread doing the main work, another handling physics, another helping with the AI, I don't know... Even in the best designed multithreaded game the cores will do different things, and some of those things will just not require as much CPU effort as others.

Edit: never mind, I should have read the whole thread first. EternalAlpha has already explained it better

Actually, it is possible to have a game engine evenly split its tasks across all available core, it's just a lot more difficult and time consuming. But the coarse threading approach (different cores for different engine modules) isn't just inefficient, it can lead to slow downs as one core maybe overloaded while the others are doing nothing.

Since the optimal method, evenly splitting the work load isn't the best approach (time/money wise), Valve has taken a different approach to it. They call it 'Hybrid' multi-threading. It works only on 4 cores or more. One of the 4 cores is set aside as the controller. It does nothing except tell the other cores what to do. All tasks are handed to it, and it checks how much each core is working, before allocating the task to the core that's lazying off. This approach does lead to one whole core being taken out of the processing game, but leads to the other cores working much better. Like in the OP's case, where one core is slaving away, leading to only 50% overall CPU utilization. Even if one core is tied up controlling the others, provided there is enough to make the 3 other cores work at max, it will lead it 75% CPU utilization.

However, I do think aevm is correct, that we will see inefficient use of multi-cores more and more. It seems developers no longer try to sqeeze every drop of performance out of available hardware, but rely more or brute speed of new and upcoming technology to smooth out performance problems caused by non-optimal coding.

I get the exact same thing with my system. Fourth core pegged, the rest a little below 50%.