gpu usage drops to 0 in game 1-2 second freeze

I recently upgraded my gpu and now I'm playing some games. I played Chivalry medieval warfare, no problems. Now I'm trying to play Total War: Rome 2 and when I'm in battle the game freezes for a brief moment, and it does so constantly. I was curious about what was happening so I opened up msi afterburner to see what was happening to my gpu when this freezing occurs. It seems to be that the gpu usage drops to 0% every few seconds inexplicably and the gpu usage never even reaches 100%, it just hovers around 50-60%. The temp goes to a maximum of 75 degrees, so it can't be overheating. I was curious what would happen in other programs so I used kombustor and even when at 100% usage and 75 degrees, this freezing doesn't occur. So is it just the game? Do I need to do some tweaking with afterburner? It is all on defaulted settings so I didn't mess with anything. I doubt it is the hardware itself because it works fine elsewhere, perhaps it's just the game? Any help is highly appreciated.

Here are my specs:
Operating System
Windows 7 Home Premium (x64) Service Pack 1 (build 7601)
Install Language: English (United States)
System Locale: English (United States)
Installed: 3/13/2013 11:44:29 PM

System Model
iBUYPOWER Computers

Processor a
3.40 gigahertz AMD Phenom II X4 965
512 kilobyte primary memory cache
2048 kilobyte secondary memory cache
6144 kilobyte tertiary memory cache
64-bit ready
Multi-core (4 total)
Not hyper-threaded

Main Circuit Board b
Board: ASUSTeK Computer INC. M4N68T-M-V2 Rev X.0x
Serial Number: MT7011K15800162
Bus Clock: 200 megahertz
BIOS: American Megatrends Inc. 0501 08/03/2010

Drives
1000.10 Gigabytes Usable Hard Drive Capacity
382.40 Gigabytes Hard Drive Free Space

ATAPI iHAS124 B SCSI CdRom Device [Optical drive]
DTSOFT Virtual CdRom Device [Optical drive]
DTSOFT Virtual CdRom Device [Optical drive]
DTSOFT Virtual CdRom Device [Optical drive]
DTSOFT Virtual CdRom Device [Optical drive]

Hitachi HDS721010CLA SCSI Disk Device (1000.20 GB) -- drive 0, s/n JP9911HZ111YPU
Kingston DT 101 G2 USB Device [Hard drive] (7.80 GB) -- drive 1

Memory Modules c,d
4096 Megabytes Usable Installed Memory

Slot 'DIMM0' has 2048 MB
Slot 'DIMM1' has 2048 MB

Local Drive Volumes

c: (NTFS on drive 0) 1000.10 GB 382.40 GB free

Controllers
ATA Channel 0 [Controller]
ATA Channel 1 [Controller]
NVIDIA nForce Serial ATA Controller (2x)
Standard Dual Channel PCI IDE Controller

Display
AMD Radeon HD 7900 Series [Display adapter]

 

A HD79xx slurps a lot of juice, if your PSU can't supply that, this could be the result.

What make/model# PSU do you have, what age is it?

 

I have a Thermaltake TR2 600W. I bought it at the same time as my new gpu, which was about a week ago. I did some research and my system isn't supposed to take more than 500-550W. Is there a way to find out if I need more power?

 

The easiest way of testing either is by switching parts with another (high-end) machine, finding someone with that rig may not be so easy.

This PSU? http://www.newegg.com/Product/Product.aspx?Item=N82E16817153166

Newegg have been selling it since early 2005 so it's an older design using dual 12V rails, 23A and 20A - that doesn't mean it outputs a total of 43 Amps on 12V, probably closer to 35, maybe less than that.

What you should be aiming for is a modern, quality PSU with a single 12V rail capable of giving 40+A. Depending on which model HD79xx you have, I'd suggest a Seasonic or XFX of 550 - 650W+. If your next upgrade is to an Intel-based 'board with an i5, I'd opt for this: http://www.newegg.com/Product/Product.aspx?Item=N82E16817151119

If you're unsure which upgrade will be next or don't like the price or want to stick with AMD, look to these: http://www.newegg.com/Product/Product.aspx?Item=N82E16817151096 http://www.newegg.com/Product/Product.aspx?Item=N82E16817207014

 

You mean the 12V that plugs into my Mobo? I can only plug one of those in (it's an 8-pin that separates into two 4-pins) because my mobo is pretty old, I'm going to be upgrading it, cpu, and RAM this holiday season. How many Amps should I have to run my current system? Is there a way to calculate that?

 

Greetings, BigglezMcGee.

In Satrow's absence I'll post a good online calculator link here.

 

Unfortunately that doesn't tell me amps. Could this all possibly be bottlenecking? My cpu is pretty significantly weaker than my gpu, and so is my RAM. Could it simply be that too much is being demanded of my weaker hardware and it's causing freezing??

 

Update your drivers first, fully patch the game, lots of problems fixed even in the fourth patch.

http://wiki.totalwar.com/w/Total_War_ROME_II:_Patch_4

EDIT Until you witness the problem in all games or most games it's a problem with ONE game so I wouldn't suspect your computer at all ATM let alone power supply but anyways-

After a good gaming session 'not benchmark' feel the side of the psu is it warm or hot? Download and install speedfan and post your temps, before and during a gaming session.

Is Vsync on? This will limit your fps to your monitors refresh rate. Download and install fraps and watch your fps while playing, all lcd's run 60Hz so if vsync is on your fps will be 60Hz.

Disable vsync in the games options then monitor your gpu usage.

Strategy games aren't usually gpu intensive but they are cpu intensive

Type perfmon in windows search and monitor your cpu usage during the gaming session, first is it at 100% all the time?

To test the power supply run kombustor and Intel burntest 'for all cpus',this will put maximum stress on the entire system, if your psu was causing the problem your would see the drops outs in gpu usage or the computer will crash, monitor temps throughout.

Finally as a punt block the game in your software firewall 'unless you play online'

Not memory you have 4GB but you should run memtest anyway.

All programs listed are available at MG.:major

 

As an aside: the calculator displays power requirements in wattage.

P=IE [Power (watts) = Current (amps) times Voltage (volts)]. Basic electricity.

 

Sorry that I haven't responded. I did some research and found out that I needed to turn unlimited graphics memory on, it's working fine now. Thanks anyways, guys!