I am totally new to this . . . .

[qwerty]

I am trying to build a computer, and I have never done anything like it before, and it is all a bit daunting.

how an OEM is different to normal OS?
What is the cache of a hard drive?
what is an expantion slot (on the mother board)?
what is a PCIe slot (on the mother board)?
What is the difference between SATA and SATA III?

I am looking at an AMD FX-4170 processor, quad core, 4.2GHz. As far as I can make out, this is by far the best bang for buck on the market at $130. I don't want more than four cores because I have heard that they cause the older versions of photoshop to run slower.

[RickyTick]

I am trying to build a computer, and I have never done anything like it before, and it is all a bit daunting.

how an OEM is different to normal OS?
OEM or System Builders versions are nontransferable between different pc's. Once you install it, it is connected to the bios of the motherboard. It also does not come with Microsoft support.
Retail versions come in a pretty box and you get Microsoft support. You can also install it on multiple computers, but only one at at time. The retail box also has both 32-bit and 64-bit versions.


What is the cache of a hard drive?
Refer to this link. http://en.wikipedia.org/wiki/Disk_buffer
In a normal computer like what you're going to build, you would not be able to tell the difference between 32 and 64mb cache.


what is an expantion slot (on the mother board)?
This is a great article on expansion slots. I would encourage everyone to read it all the way through.
http://www.hardwaresecrets.com/article/Everything-You-Need-to-Know-About-the-PCI-Express/190


what is a PCIe slot (on the mother board)?
I think we covered this in the article above. A PCIe slot is an expansion slot.


What is the difference between SATA and SATA III?
SATA 3 is simply the latest version of storage interface.
This might help. http://en.wikipedia.org/wiki/Serial_ATA



I am looking at an AMD FX-4170 processor, quad core, 4.2GHz. As far as I can make out, this is by far the best bang for buck on the market at $130. I don't want more than four cores because I have heard that they cause the older versions of photoshop to run slower.
You may want to take a closer look at the Intel i3-2120.

[qwerty]

Thankyou so much. Just one more question though, why should I choose the i3 2120 over the FX-4170? It is only $10 cheaper on amazon, it is older, it is 0.9GHz slower, it has two less cores, and doesn't work with the higher speeds of RAM. Is there somthing I am missing?

[RickyTick]

Here's a couple of reviews to read through.

http://www.ocaholic.ch/xoops/html/modules/smartsection/item.php?itemid=773&sel_lang=english

http://www.tomshardware.com/reviews/gaming-fx-pentium-apu-benchmark,3120-10.html

[qwerty]

One of those reviews doesn't list the fx-4170.
The other says the 4170 isn't very much faster than the i7-920 ie. it is still faster. (The i7-920 also costs twice as much!)
The one you recomended, the i3, is probably slower than the i7-920, because it has less cores. Why should I choose the Intel over the AMD?

[qwerty]

oh and I forgot to say that the AMD appears to have a slightly bigger cache and supports faster RAM . . . I don't know if this would make much of a difference for my purposes though . . .

[RickyTick]

It's really just a performance issue. The i3-2120 dual core outperforms the FX4170 quad core, and uses less power and generates less heat. The 4170 overclocks well and my perform better in some circumstances, but overall the i3 is a better value. There's nothing wrong with the FX4170. If you happen to be a fan of AMD or just like something about them, then go that route.