Time to upgrade E6420, or perhaps something else?

[badenglishihave]

Man. I have been out of the o/c scene for over 1 1/2 years (left college, started job, life, etc.) I need some advice on whether or not to upgrade my CPU to perhaps an i7 920. Current system specs:

Intel Core2 Duo e6420 4MB L2 @ 2.13 GHz (I'll get to that later)
G.SKILL 2x1GB DDR2 800 2.0V 4-4-3-5 CAS4 @ stock timings
ASUS P5B Deluxe LGA 775 Intel P965
MSI NX8800GTS GeForce 8800GTS (G92) 512MB
HT | OMEGA Claro Halo PCI Sound Card
BenQ 24" 1920x1200 G2400WD 5ms (2ms g2g)
Toshiba 46" 1920x1080 LCD 120Hz
Windows 7 x64 Ultimate

I have had my 6420 clocked at 3.1 GHz but I ran into a problem when I upgraded my video card: apparently the P5B and 8800GTS don't play nice with each other, and any OC of my CPU resulted in my PCIe frequency being locked at 1x which kills HD video decoding and gaming.

Anyways... yesterday I noticed that while playing 1080p video and browsing the web, my audio would stutter now and then. I also have occasional slowdowns in graphically intensive areas while playing some older games (Guild Wars, Counter Strike: Source). I plan on picking up CoD4 as well as Guild Wars 2 and perhaps Dragon Age. I also do some video encoding so I can put various media on my portable player and phone (this is why I'm considering quad).

As such I am looking to upgrade on ~$700 or less. Here are my options as I see them in order of price from lowest down to the highest:

1. Upgrade motherboard so I can get my CPU back to 3.1 GHz, and get 4GB RAM. Possibly get a new video card (recommendations?).
2. Upgrade motherboard, get 4GB RAM and replace E6420 with E8400. With this option I would also possibly get a new video card.
3. Purchase i7 920, 1366 motherboard, and 4GB RAM. Keep existing video card.

Thoughts?

 

[redduc900]

I have had my 6420 clocked at 3.1 GHz but I ran into a problem when I upgraded my video card: apparently the P5B and 8800GTS don't play nice with each other, and any OC of my CPU resulted in my PCIe frequency being locked at 1x which kills HD video decoding and gaming.

Here's a few solutions for the PCI-E 1x bug on the P5B and Gigabyte P35 series of boards...

1. Disable "PEG Force X1".
2. Set the NB Vcore to 1.45v or below.
3. Overclock or underclock the PCI Express reference clock (up to 15MHz either way).
4. Set PCI Synchronization Mode to Auto.
5. Set PEG Link Mode to Normal (instead of Auto).

 

[badenglishihave]

Here's a few solutions for the PCI-E 1x bug on the P5B and Gigabyte P35 series of boards...

1. Disable "PEG Force X1".
2. Set the NB Vcore to 1.45v or below.
3. Overclock or underclock the PCI Express reference clock (up to 15MHz either way).
4. Set PCI Synchronization Mode to Auto.
5. Set PEG Link Mode to Normal (instead of Auto).

I already tried all these, mate . I found a forum that discussed these fixes but none of them seemed to work. CPU-Z always reports 1x for my PCIe multiplier. I'm probably doing something wrong but at this point it'd be easier to just get a new setup.

 

[doublejack]

At this stage of socket 775's life cycle, I really can't recommend you purchase a motherboard and/or processor. This is particularly true since you only have 2gb of memory. Why sink money into a motherboard, memory, and possibly even a processor on a platform that is approaching EOL... especially since you can spend a little more and go with an i5/i7? So that means options 1 and 2 aren't very appealing IMO. I don't think it is a wise use of resources.

However, option 3 has a drawback as well. I have to believe that at 1920x1200, your 8800GTS is starting to show its age. If you sunk money into an i7 setup you would absolutely be GPU limited. Realistically, you'd see a bigger improvement by upgrading your vid card.

So, my advice is to upgrade just your GPU. You'll see a benefit assuming you game at native res, a new vid card can migrate to an i5/i7 setup if you choose to pursue that upgrade path later on, and it should allow you to restore your overclock again since the troublesome 8800GTS is gone. A C2D running in the 3.1-3.2GHz range is plenty fast enough to run practically all current games at 19x12.

If you want to, you can also add 2gb of memory for around $50. DDR2 won't make the transition to a new platform, but $50 isn't a huge loss. If you are really set on getting a whole new setup, then option 3 is the only one I can suggest with good conscience.


Finally, as a fellow P5B Deluxe owner I'm bummed to hear about your troubles with the PCI-E link bug. Have you tried flashing to the latest bios? I've gotten 2+ years of service out of my P5B so far and I'm still as happy with it as the first day I got it. I upgraded to the 9800GX2 a little more than a year ago and thankfully did not run into that problem.

 

[badenglishihave]

Finally, as a fellow P5B Deluxe owner I'm bummed to hear about your troubles with the PCI-E link bug. Have you tried flashing to the latest bios? I've gotten 2+ years of service out of my P5B so far and I'm still as happy with it as the first day I got it. I upgraded to the 9800GX2 a little more than a year ago and thankfully did not run into that problem.

At the time I was trying to fix the problem (Fall 2008) I flashed the BIOS to the latest version. I then spent about 2 hours trying to change the BIOS settings in the afore mentioned post but to no avail.

Thank you very much for the other advice! It completely slipped my mind that upgrading my graphics card would allow me to overclock my c2d without the PCIe 1x bug. That will probably be my plan of action for now, then upgrade my CPU by the end of 2010.