I wanted to increase the speed of the CPU without buying a new motherboard and chipset. I currently have a Gigabyte GA 880GA UD3H Motherboard with a AMD Phenom II X6 1045T. So I was thinking of overclocking the current chip or buying another AMD processor that can fit the motherboard and then overclocking it. I did not want to spend too much money of the customization. I use the PC for mostly, internet, documents, video, some graphics. No gaming. I have a NVIDIA Geforce FT 730 card.
You didn't specify which version of your motherboard you have.
There is only one version which can support a AM3+ Processor which are the FX series which are more powerful and faster than the Phenom II.
If you have the last version of your motherboard, version 3.1: GA-880GA-UD3H (rev. 3.1) | Motherboard - GIGABYTE Global
Depending on which version of your Motherboard you have installed will depend if you are able to install the FX Processor as an upgrade.
In case you don't know which version you have here is how to find out:
If you don't have a Version 3.1 then the only choice you have is to Overclock your existent processor.
I would suggest you go to an Overclocking Tech Website like Overclockers.com - Forums or Overclockers.net. There you will probably get your answer as to high you can Overclock your Phenom II processor from here: Overclockers Forums.
Found this thread at https://www.overclock.net/forum/10-amd-cpus/1346977-overclocking-phenom-ii-x6-1045t.html concerning overclocking your processor.
Wow how confusing. They should have changed the model number not just the revision to 3.1 as it is the only AM3+ board of the bunch. All the others are just AM3 so yes on those a Phenom II is as far as you can go.
Yeah, I needed to edit my reply afterwards because I assumed all the versions supported AM3+ processors until I saw the N/A meant it didn't support AM3+ processors under the BIOS catergory. Then I saw the only version was 3.1 which did show a valid BIOS Version (BETA BIOS) which I validated at the download page.
You would think the same motherboard model would all support basically the same processors in all versions. That was the false assumption I was under until I started checking each individual models supported CPUs.
What threw me off was all the versions showed the FX series processors except versions 3.0 and below was not supported. Why even bother to show a Processor that wasn't supported on the Support CPU page.
I have known that AM3 motherboard can be used to install AM3+ Processors. As per this question under google:
Actuall to my knowledge and AM3+ will fit but not work. I know of no exceptions. I have 3 different AM3 boards and could not upgrade to anything later than Phenom II. Now you can use a Phenom II in an AM3+ board.
According to what I just read an AM3 can fit a AM3+ but not vice versa. The AM3 has 941 pins and an AM3+ has 942 pins so not possible. Now I am sure that doesn't mean that around the time AM3+ was about to be adopted that some AM3 board models could have been sold as AM3 but actually had the AM3+ socket and just awaited a bios update. That is probably the more likely scenario.