Random crashes and long boots

Hi - i recently bought a (just about) completely new system which has 2 main problems - ive had a bit of a look online already for possible solutions and i have an idea but i'm not too sure so im just looking for some specific validity of my problems.


Computer Specs:
Intel E8400 cpu
Gigabyte GA-EP45 UDP mobo
ASUS Radeon HD 4870 1gb video card
*master 650w psu (im not sure about the brand here.. it has master in capital letters with the m and r in red..)
very old IDE hdd which is currently slave** to
Samsung DVD drive
running Windows Xp Professional



Problem 1:
Ok so far as i know this only happens when i play certain games - games and net are mainly what i use my computer for. In playing games such as Mass Effect, Bioshock, Crysis Warhead, Oblivion and Neverwinter Nights 2 the games will run for a random period of time before the computer completely turns off. No warning, the first thing that happens is the monitor flashes with a 'no signal' message (and i can sometimes, hear the game continuing despite this) and then about 5 seconds later its off, like ive held the on/off button for 8 seconds. This often happens at more graphics intense moments in the games (special effects etc) but can randomly happen whenever. Ive had it occur over an hour into a game, and within 30 seconds of starting. It has never happened in any games by Valve (tf2, portal, episodes etc), nor Mirror's Edge, fallout 3, supreme commander: forged alliance, or Call of Duty 4.

I'm fairly sick of it - does anyone know anything that can help me out? if i need to download any system spec programs or those apps that measure psu wattage im happy to do that


* ive got a feeling it might be a bit of a bad psu, coz while a 650w should be enough to run my system, ive looked around and people with problems in my ballpark have had trouble with their PSUs. not sure enough to buy another one though.

Problem 2: As soon as you turn the computer on, it beeps like its starting up... but nothing happens. the screen doesnt change, and about 10 seconds later it beeps again.. and again... and then it restarts. as in turns off for a few seconds, and turns itself back on again and tries vainly to boot up. it can take anywhere from a minute to 10 minutes to start up, but when it does it's fine. also, restarting the computer once im in windows happens normally - no problem there.


** Since i haven't bought an sATA hdd yet i just connected the only ide cable that comes with the mobo to both the optical drive and the hdd. i had an idea that the computer was taking a while to recognise which was master and slave and so wasn't starting - but this is just speculation really.

I go on a lot but if ive left anything important out could someone let me know - that would be great!

cheers

First, I would swap the HD and the optical. Make the HD the master. Check in the BIOS to make sure it's also the first boot device. You can also check to make sure quick boot is enabled. I don't believe this has anything to do with your shut down problems, however, it could speed up the boot process.

I believe you have a cooler master psu. They are a mid range quality psu. How many amps are on the 12v rails?

What kind of RAM are you using?

The stats for the psu will be on the side of it. It should have it broken down by each rail. You want to find the 12v rail(s) and add up how many amps are on them total. It's an important number when calculating if it has the nutz to push your video.

That's likely the problem. 34.5 amps on the 12v rails is a bit weak, specially if it's an aging psu.

This is a high quality psu
http://www.newegg.com/Product/Prod [...] 6817139005
Look at the amps on the 12v rails compared to what you are using. It has 52.8 and yours has 34.5.

I believe that when you hit a graphics intense point, your psu isn't capable of putting out sufficient power and shuts down.

Most graphics cards draw twice as much with a 3D load than they do with a 2D desktop load. That's enough to cause "random" crashes and reboots.