Starcraft 2 low framerate

[LIZZARD]

Hello,

 

I have recently swapped out my NVIDIA GeForce 9500 GT 512MB for an XFX ATi Radeon HD 5770 1GB. Problems occur while playing Starcraft 2 Heart of the Swarm. With my old card, I would get around 45 fps steadily throughout the game. Now, with my new card, I start off at around 80 fps, but later during the game, it drops down to 10 fps (even less when in heavy battle). This is weird, considiring that I use exactly the same settings (1440x900@75Hz, everything else set to the lowest).

 

These are my specs:

 

Fractal Design Core 1000

Intel Core 2 Duo CPU E6550 @ 2.33GHz (not overclocked)

Dell 0RY007 Motherboard

4096MB RAM (DDR2)

320 GB Seagate SATA HDD

640 GB Hitatchi SATA HDD

Some random optical drive

XFX ATi Radeon HD 5770 1GB (not overclocked)

ASUS Xonar DG Soundcard

Corsair CX430 PSU (430W, 80+ bronze)

Windows 7 Ultimate 32bit Service Pack 1 (should be noted I was using Windows 8 Pro 32bit with the NVIDIA card, I downgraded to Windows 7 at the same time as installing my new GPU)

 

Is there any way to fix this?

 

Thanks in advance!

[AndyCapets]

What is you PSU wattage ?

[skullbringer]

Maybe psu throttling...? Whats your psu wattage

 

Otherwise make sure you have the latest graphics drivers

[LIZZARD]

What is you PSU wattage ?

 

Maybe psu throttling...? Whats your psu wattage

 

Otherwise make sure you have the latest graphics drivers

Sorry, forgot to mention that my PSU is a Corsair CX430 (430W, 80+ bronze).

The graphics drivers are up to date.

[AndyCapets]

Sorry, forgot to mention that my PSU is a Corsair CX430 (430W, 80+ bronze).

The graphics drivers are up to date.

Yeah no, it's not the PSU I think.

It might be the OS, usually it is, try reinstalling W8 if you can, and this time the 64Bit version, 32bit versions are no longer interesting on a PC imo

[LIZZARD]

Yeah no, it's not the PSU I think.

It might be the OS, usually it is, try reinstalling W8 if you can, and this time the 64Bit version, 32bit versions are no longer interesting on a PC imo

Unfortunately I can't, I installed my W8 on my brother's pc, so I don't have a space license. Is it possible to install a 64bit os on an originally 32bit system? I have always thought that that was impossible, otherwise I would have done it ages ago.

[LIZZARD]

Ok, so I have installed the 64bit version of Windows 7 ultimate. Although i have more ram available now, it did not make a difference. Is there any other way to fix this? It only happens during multiplayer btw, not during the campaign.

[NotRed]

Ah you have the Radeon HD 5770. I have one too and i get 50-60 fps never dipping below 30fps and thats in 4v4. Sounds like your power supply is below the reccommended which is 450w. You might want to consider upgradeing the psu since not enouph wattage = throddle.