Need help please! upgrading old system!

The same Sapphire HD 4870 1GB is cheaper at Newegg.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102801

I agree that's the best upgrade you can do on your budget.

Yes, add an extra stick of the same type of RAM, if you can. There's a big difference between 2GB and 4GB in gaming. Read this:
http://www.bit-tech.net/hardware/2008/07/08/is-more-memory-better/5

1. I suggest you do these upgrades with your $300 for now.

2. Later, get a WD6400AAKS hard drive ($75 at newegg these days) and a 22" monitor. This one is pretty good, for example:
http://www.newegg.com/Product/Product.aspx?Item=N82E16824009145

3. Even later, think about getting a new MB and CPU. Something like Q6600/GA-EP45-UD3P or Phenom 9850/K9A2 Platinum, for example. Each combination is about $400. The speed is identical (each wins some benchmarks), The first combination overclocks better. The second combination does Crossfire better, without any PCI-E x8 bottlenecks. Either would be an improvement over what you have and future-proof i.e. allows Crossfire.
Read this to see what you can expect from various CPUs:
http://www.legionhardware.com/document.php?id=770&p=5

4. Finally, when you can, add a second video card.

What resolution do you game in? I hate to be the bearer of bad news but the components you want to upgrade aren't the ones that are needed. If I were you i'd get a gigabyte UD3P mobo for $135 ($115 after MIR) and pair it with a E8400 ($179) and keep your other parts. Then in a few weeks by 2 X 2 gigs of ram for like $50. Then when you can save for a video card upgrade, you'll have the benefit of the future pricing and future cards.

Doing it this way will be the best of both worlds. An E8400 with at 8800 GTS is a great setup versus a AMD 4400+ with a 4870. You'll notice a huge performance upgrade with the first versus the latter.

I'd love to see you prove that one  

Edit:

This article shows the E8400 getting twice as many fps as the X2 4400+. I suspect you've seen benchmarks like that and that made you think of a CPU upgrade first. However, these results are with high-end video cards (HD 4870 X2 or GTX 280).
http://www.legionhardware.com/document.php?id=770&p=2


This chart shows the HD 4870 512MB getting 110 fps where the 8800GTS 320MB gets 49 fps.
http://www.tomshardware.com/charts/gaming-graphics-charts-q3-2008/Call-of-Duty-4-v1-6,745.html
I'm guessing the HD 4870 1GB would get 115 fps or so.
However, these results are with a high-end CPU (typically GPU benchmarks are done with overclocked quad CPUs so the CPU is not a bottleneck).

Based on this, it's impossible to say if the weak CPU/good GPU is better or worse than the weak GPU/good CPU combination. I suggested the weak CPU/good GPU combo because the GPU is usually the most important part in gaming. I'm not saying you're wrong. I'm just saying I don't know for sure if you're right or wrong. I guess we need to do more research here...

What cpu socket do you have? If you have an AM2+ and if your mobo has a good bios update, you may be able to run the phenom II coming soon next year. I doubt that mobo will update that far, but i would stay in the AMD upgrade line long enough to see what happens with the phenom II and your bios updates. The phenom II is supposed to be out Q1 2009.

+1 for aevm's 1st post.

Aevm,

I'm not able to pull up those benchmarks, but what resolution are they tested at? He said he has a 19 inch acer, and i'm guessing he games at either 1280 X 1024 or 1600X1200. Based on the age of his system, the first is probably more likely. If we are basing his upgrades around that resolution, all those cards you mentioned are extreme overkill and the CPU is way more of a bottleneck. If you assuming he is gaming at 1080p resolution, then you are 100% correct the video card needs to be as powerful as possible.

Let me add one more thing. I have a 22 inch samsung and I game at 1680 X 1050. My old machine was a AMD 4000+ oc'd to 2.7 with a HD 4850. I transferred that card to my new rig, which is a Q9550 and my framerates more than doubled. Now, if I was gaming at 1080p or 1920 X 1200 or something higher. I would not have noticed nearly this improvements, but since I game at lower resolutions, the bottleneck is tied more to the CPU

True. On his 19" monitor the CPU matters a lot. Yeah, maybe the MB/CPU thing should come first.

The benchmarks I linked are at 1920x1200 and 1680x1050 respectively.

@odogxx: are you using the PC for anything intensive other than games? That could be a reason to start with the MB/CPU too.

If you have an am2, you could get a 9850 Quad at the egg for 160. Oc to 3.0 ghz and you can play anything out there.

Then get a HD4850 for 150.

I would never buy an AMD right now. You could have a E8400 at 4 gigahertz so why settle on a chip thats $20 cheaper and lose 1,000 mhz.

because he has a 300 dollar budget for an upgrade, not a new system, mobo etc.
My way he can get a new video card and processor and be just fine.

No just gaming, however I surf the web now and then, I play at 1440X900 max resolution, I'm not resolution fanatic.