The computer will only draw as much power as it needs from the power supply. The power supply will not force all the power it can on the computer. It doesn't work like that. Which is why when your computer is plugged in but off, no power is used.
As long as your PSU is of adequate (or larger) size to power your system, your system will pull only what it needs from the PSU. For example, if your system needs 300 watts, it won't matter if you have a 400 watt PSU or a 750 watt PSU. Your system will still pull just 300 watts.
If you were to upgrade your GPU to something like a 4670, you would be able to play something like cod4 at high (not extra) settings with AA off at 1920x1080 without dropping below 30FPS. This is based on the performance of my radeon 3870, where I can max everything except the AA and get never below 30FPS. It would be worth the $70 but in the future you would want to get a new computer. Especially since the CPU would hold back any card better than that in most games.
The question of cost effectiveness is actually your third question to ask. The first is...
What games (applications) do you want to play, and at what settings/resolutions?
What is your budget?
However, in almost any case, a cheap laptop/netbook for "internet browsing and office applications" along with an "easily upgraded desktop" is probably going to be more cost effective. This is because "desktop replacement laptops" (IE: gaming laptops):
1. Drain battery power quickly. (Think a typical maximum of 3 hours battery life.)
2. Cost quite a bit. (At least $1.5k USD.)
3. Are heavy and bulky. (You lose the "ease of portability" factor.)
4. (Other reasons)
Just like the PC building guide on this website asks, however, the above 2 questions are the most important when deciding on a new computer.
i bought an hp pavilion laptop like a year and a half ago. i do not recommend it, as it has been nothing but problems, but i have been able to do some light (gta3) gaming on it. it does everything mildly well, instead of having strong points and weak points.
the intel core 2 duo 2ghz cpu is plenty decent, 4gb of ram are plenty, the 320gb hard drive (which failed twodays after warranty) holds (held) plenty of data, and the dvdrw drive was nice and versatile. oh and the intel graphics suck!) keep in mind, though, that especially on larger laptops the batteries dont last very long. also, especially on laptops wih larger screens, the backlight uses up a lot of bettery power. When on full brightness it seems to decrease battery life by a good half hour or more...
My budget is about $1100, I want to be able to play FPS games such as Unreal 3 (a bit dated, but fun as hell!) at high-ish resolution (My 1366x768 at the moment is quite nice) with a decent frame rate. I would like to be able to play most new-ish games (DoW2, Oblivion, Far Cry 2) at a high-ish standard.... ish!
I'll need to buy a completely new desktop if I'm going to use it in University as this one is technically the family computer (which i use the most! )
Well, with your total $1.1k (I am going to assume USD) budget...
1. About $400 is the minimum price you will find a good netbook/notebook that won't cause you eye strain. (However, I am of the opinion that a 11-12" screen is the minimum that is acceptable. Other people may disagree.)
Therefore, when looking for this netbook/notebook, you will probably end up with a low-end mobile Intel Pentium or Atom cpu, integrated Intel graphics, 2 GB of ram, and a ~120 GB HD. For a computer to be an office computer (and nothing else): read = note taking, no game playing, internet browsing, and no major media storage... this is perfectly acceptable. Just remember to buy the extended warranty AND regularly copy your notes, etc. to the the desktop's drive.
2. As such, this will leave you with about $700 for a "gaming desktop." Once you include the OS (probably OEM Student Windows 7 64 bit = ~$50) and peripherials (monitor = ~20" WS LCD for about $100, keyboard, & mouse = ~$30), that leaves you roughly $520. (As such, you see the problem...)
In my opinion, if you were to simply copy/paste "pick" the best mainstream computer build from the post mentioned in my earlier post, it would be the following:
CPU: AMD Phenom II X3 720 Black Edition Heka 2.8GHz Socket AM3 95W Triple-Core Processor Model HDZ720WFK3DGI - OEM
MOBO: ASUS M4A785TD-V EVO AM3 AMD 785G HDMI ATX AMD Motherboard - Retail
RAM: G.SKILL ECO Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL7D-4GBECO - Retail
HSF: Sunbeam CR-CCTF 120 mm Core-Contact Freezer CPU Cooler W/TX-2 - Retail
HDD: SAMSUNG Spinpoint F3 HD502HJ 500GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
PSU: CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 ... - Retail
GPU: XFX HD-577A-ZNFC Radeon HD 5770 (Juniper XT) 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card - Retail
DVD: LITE-ON Black 24X DVD Writer Black SATA Model iHAS424-98 LightScribe Support - Retail
Case: COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case - Retail
Thermal Compound: Comes with heatsink.
This build will allow you to play games at mid. to max. settings at a monitor resolution of 1920x1080 or less
However, this comes with three caveats:
1. This is a simple copy/paste from the article. Whenever you actually ask for advice about the build, that day's best builds and prices and will be different. (You will probably end up with slightly better.)
2. This is overbudget if you need to buy a monitor as well. (As such, when you make the post, make sure to request pricing that includes everyone you need... and don't need.)
3. (Other personal points of contention): You may be better off buying from an OEM instead of building your own at this price level. (Example: If you know what you are looking for and have little experience in building computers, some people are better off going to HP, Dell, etc. and "custom building" their computers there.) You get a warranty for the entire system... and their technical support has to deal with any issues you face. (If you build your own, you are at the whim of your own experience and that of "Internet users.")
With the third cavaet, some people will completely disagree with me on it. However, I have two former friends that are now on the bad side of this boat. (When they were friends, they asked me to build their computers... and I did. However, due to personal issues, they are no longer friends... and they have some issues. Due to the mutual decision to not speak to each other ever again, they now have to deal with several different tech support numbers who all, in general, say "it is not our problem... call the support for that other component.")
With the above said, though, building your own computer is... eventually... the best thing you can do. My computers fell in line as such:
1. "Bought as a pre-built in a store. (Example: Best Buy)"
2. "Go online, due to my limited knowledge, and slightly modify a base configuration." (Example: HP, Dell, etc.)
3. "Go online, due to more knowledge, and heavily modify a base configuration." (Again, HP or Dell... or, perhaps, one of the sub-builders that will build a pc for you based on parts they order.)
4. "Buy my own parts and build my own computer." (The step many on these forums are and have been at for years.)
I recommend either 2 or 3 for you, as... one mistake... 1366x768 is actually a very low resolution. (Which makes many games more dependent on the cpu than the video card, since higher resolutions mean that your video card must do more of the work.) The "mainstream" desktop gaming resolution is now 1680x1050 on a 22" WS LCD monitor.
Hmmm.... Fitting a 22" monitor into student accomodation may be a bit tricky...
I have basic knowlege of building PCs, I've botched a few out of old components from old and/or broken PCs. (I have a Windows 2000 in the attic with 4 hard drives and 2 NICs ) I may go with option 2 or 3 depending on whether I can find something that's close to what I want online, pre-built.
If you go with one of the OEM pre-built options, just remember the following things:
1. Don't expect to be able to upgrade anything it but an increase in the ram (if it has extra slots), an extra hard drive, and ... maybe... the video card. (And, never tell them you did it... or it voids the warranty.)
2. You may be able to get a "combo deal" by buying both the netbook/laptop and the desktop at the same time. (Potentially saving you ~$50 to $200 dollars.)