Which CPU would maximize NVIDIA 7800 GT?

[labu]

Hello everyone.  My computer recently got upgraded from a very old Pentium III PC.  I bought the 7800 GT but seems couldn't get a lot FPS improvement in FS9 especially when I was flying over the Hong Kong 2004 scenery.  I tried 3DMark05 7800GT got 5723 3DMarks but only 3544 CPUMarks.  My new computer only get around 15~20 FPS when looking at the dense building area in the HK 2004 Scenery.  Also, I fly the Eaglesoft Cirrus SR22 G2 in VC get also only 15~20 FPS.  For the default scenery, sometimes there also are only about 20 FPS (100% default traffic and looking at airport), about 40 FPS when flying over the default Chicago.  

So I'm guessing if my CPU is not power enough to work with the 7800 GT since I'm using a 2.8 GHz Celeron D.  I have checked several topics here and found that there are just a few people mentioned Celeron D CPUs, but mostly AMD's CPUs.  I'm now considering to buy a better CPU which could work on my motherboard (support LGA775 533/800 MHz bus).  I might buy a 3.4 or 3.6 GHz CPU or even the 3.2 GHz Extreme Edition CPU.

Any suggestion to me?  Which is the minimum CPU requirement to maximize 7800 GT performance?

Here is my current configuration:
2.8 GHz Celeron D
XFX 7800 GT with 256 MB
2x 512 System RAM (I don't know the type name but they should be the latest type and fast enough)
Intel D915PLWDL motherboard



Sorry for my "strange English"

[ctjoyce]

Well you need to get into the pentium famly (4) and not a celeron first off, and second off the 7800GT only scores about 6500 3DMarks so your only 1000 off. If I were you ide look at a 650 Prescott.

Cheers
Cameron

[Alphajet_Enthusiast]

Yeah sticking a card into a pc wont do much good you have to look at the package.
Personally I give preference to Athlon processors but it also depends on the motherboard.

My motherboard is designed for athlon processors and especially for the Nvidia Geforce 7800GT, and as a whole the package funstions extremely well.  :)

You're probably looking at some kind of Pentium4 with Intel..

[4_Series_Scania]

Replace your Celeron D with a Pentium 4 of the same socket design (Sct 478 or, LGA 775) and you'll see a big improvement.

[ctjoyce]

Ya your problem now is that your CPU is bottolnecking the GPU. Switch out the processer (which is socket 478) for a nice 3.4Ghz Northwood, and you should get your score back.

Cheers
Cameron

[4_Series_Scania]

Switch out the processer (which is socket 478 )

The Celeron D is available in both Sct 478 and LGA 775.  

[ctjoyce]

Hmm, I lied. Just went to intel's site and its aparently a LGA775, it also has a 915X northbridge, so you'll be able to accept the 6xx series of Prescotts

Cheers
Cameron

[labu]

Thank you for all advices!

I ordered what Cameron suggested me a 650 Prescott (around $275).  The guy (sales rep.) told me a 630 Prescott should be enough for me.  I see about 100 bucks difference between 650 and 630.  But I still want to get faster one, does here anybody know what is the difference in performance of 650 and 630?  Personally the 650 Prescott

[ctjoyce]

Okey heres how it works. The prescott and northwood are two different cores, much like AMDs San Deago and Clawhammer. The difference between the 650 and 550 is that the 650 offers 64bit support, thus letting you go strate to windows Vista when it comes out. Also as far as price goes, the reason I suggested a 650 was that there would be absolutely no bottol neck at all, while the 630 has a little bit of one. As far as HT goes, all Prescott cores have it. And yes it will help in FS9. Basically because the HT can process 1.5x the amount of info as a non HT processer you can devote more processer to the task of FS9, and also not loose speed to any background tasks.

Now I know you were concirned about the extra $100, but it is worth it. Just look at this >> http://www.tomshardware.com/2004/12/21/ ... age14.html (that page to the end of the artical). Basically its only 400Mhz faster, but it makes a difference. Mabe one that the end user dosnt notice, but the computer definately does.

Cheers
Cameron

[congo]

"Only" 400mhz in CPU terms can be quite significant.

Overclocking can sometimes bring cheaper CPU's to the performance levels of their big sisters if money is a big issue. Also, a 7800 series card will thrive on a 4ghz CPU, so even a 650 Prescott would benefit from a moderate overclock on such a rig. Overheat is an issue when overclocking a Prescott (and on most CPU's), it's worth reading about in any case, so you can experiment if you still find performance inadequate.

Any AMD owners should be looking at AMD cores with 1mb of L2 cache for single core CPU's and 2mb of combined cache for dual cored CPU's. All the AMD CPU's with 1mb L2 cache per core are solid and unmatched performers.

[ctjoyce]

Indeed. As far as cooling goes, the Zalman CNPS-7000 all copper heatsink is the best way to go. Your going to have to buy the LGA 775 support bracket seperate btw. But for the amount the thing cools, its well worth the $45 you spend on it. Thermalpaste is another thing to think about. Artic Cremeque is so far the bast on the market, and for $7 a tube is well worth it. Dropped my CPU core temps about 2C

Cheers
Cameron

[labu]

After plugging the new Prescott 650 onto my board, my computer really got back many 3DMark05 scores!  I don't remember the exact values (I can't check now. you'll know why), they are 68xx about 3DMarks and 501x CPUMarks.

My computer is now down again...  Because...

These stuff...

All running by this power supply unit (PSU)

Resulting... (the fuse blowed inside the PSU) I guess the reason is "overload"

My PSU burned out..  I guess this is a 280w PSU
Sorry to bother, I have a question again..  How many watt PSW I need for powering up a P4 3.4GHz, a 7800GT, 2x 512MB ram, an IDE hard drive and a DVD writer, surely a motherboard?

Many thanks!

[Delta_]

Atleast 400W from a decent brand.  I would highly recommend a PSU from Antec or similar companies.  Getting a high quality PSU means that the risk of it dieing and killing everything in the comp is minimal.

[ctjoyce]

HIPER TYPE R!!!!!! I cant stress that enough. 640Watt max load, and the most stable on the market. Yes its $120, but for the stability it puts out, you cant beat it. However congrats on your box, and welcome to the 64bit world

Cheers
Cameron

[Politically Incorrect]

Yup for the 7800 you definately want at least a 500W psu.
That was going to be my first question after reading your inital post. Chances are your CPU had little to do with your scores