Hi there!

This is my desktop PC right now:

AMD Athlon(tm) 64 X2 Dual Core Processor 5000+, 2.61GHz

Mainboard : Gigabyte GA-M56S-S3

RAM: 6 GB (3 x Mushkin 2GB DIMM DDR2 PC2-6400U DDR2-800 (5-5-5-18 3-24-6-3))

Graphic card: NVIDIA GeForce 8400 GS (8 SM4.0 1.4GHz, 256MB DDR2 2x500MHz, PCIe 2.00 x16)

Drives:
Seagate ST3250410AS (250GB, SATA300, 3.5", NCQ, 16MB Cache) : 233GB (C (E
HL-DT-ST DVDRAM GSA-H42N (ATA66, DVD+-RW, CD-RW, 2MB Cache) : k.A. (D

Microsoft Windows 7 Home 6.01.7601 (Service Pack 1)
Platform Compliance : x64

Power: Corsair VX 550W

Its only used for playing poker but its getting really slow/laggy with around 10 poker clients open and waiting/playing on a lot of tables while running HEM(1 for now but maybe 2 later), Notecaddy and Tablescan Turbo.

A new motherboard, CPU, harddisk(SSD?) and RAM(DDR3 much faster than the DDR2 that I have?) are necessary to make it run smoothly again.
How about the graphics card? I only play on 1 monitor so that should be enough or are the new integrated ones better than mine anyways now?
Power supply good enough?
What kind of cooling system(right now its just an usual air cooler)?

The goal is to create a new stable and smooth for my poker needs.
Cost effectivness and performance for poker is key, maybe up to 500 Euro.

Thanks a lot in advance!

Greets
HP

You could upgrade just the processor but you are limited to CPUs under 100w, and don't seem to have many options worth your while. Link to options. You'll probably want a new CPU fan also.

A good option would be a Phenom II X4 955 (or similar Phenom 2 X4). Which would run $100 US but you can find used ones all over the place for much less. Again you need the 95w versions, 125w ones won't work. You will probably have to do a BIOS update on your board but otherwise all should work fine.

Here is a direct benchmark comparison between the two CPUs: Benches.

DDR2 vs DDR3 isn't that big a deal, and 6GB of either will get the job done. When upgrading the board though DDR3 is so cheap (8GB = $45 US) that it's a given, but here it's good enough. The video card is fine for your uses.

As far as cost-effective that's about the best you can do. With the extra 2 cores and added processing power you'd be okay on the CPU end of things. The rest probably has some wear & tear on it but should be serviceable enough so long as they last a while.

The other option is to gut those parts out and stick them on eBay, and go with a new board + RAM + CPU + SSD. There are other "upgrade help" threads with recommendations but 500 Euro sounds like enough to get it done.

Just to check it out, I went to Amazon France and priced an i5-3750k, MSI Z77 board, 8GB RAM, an aftermarket Hyper 212 CPU fan, and a top 128GB SSD. A very new and high-end setup. I don't know about how tax and duties work over in Euroland, but the price came out to EUR 530, so your budget seems to work.

And that's for what's effectively the best system you could justify buying, so there's a lot of room to save. I didn't shop around or anything either, just went to Amazon FR and picked the first compatible parts I saw. I could be way overestimating costs.

Thanks a lot for your help!

If I get a boxed version of a Phenom II X4 do I still need a new fan?
Would adding a SSD worth it? Would it be possible with my current mainboard?
I saw that those SSD are rather unexpensive so Im wondering if it would be good for Windows my HEM database(which is not that big) and some software.

You don't need a new fan, but part of the allure of the X4 black edition chips is that you can overclock them. In which case you don't want to use the stock fan.

SSD is just about always worth it if you have any kind of upgrade budget at all.

I ordered the CPU and a Samsung SSD.

Thanks a lot again!

Greets
HP

You're welcome. Just look up your board model on the manufacturer's website and learn how to do a BIOS update. Better to do it now before you drop the new CPU in and all of that.