Owners guide to the Porsche 996 Carrera 4

iRacing is CPU limited with HD6870 and AMD Athlon 620 processor

I recently upgraded my iRacing rig to a ATI HD6870 GPU and a 900W power supply and I can now drive triple monitors at 1920x1080 resolution. I was at 3x1280x1024 before. But, I was disappointed with the frame rate of around 35fps worst case at Road America. I'd read I should be getting 70. After some research I'm pretty sure the problem is my CPU. I have an AMD Athlon x4 620 which is a quad core 2.6Ghz chip with no L3 cache. I tried overclocking it to 3.2Ghz last night and the frame rate rises to around 43fps.

It looks like an Intel i5/i7 setup is best for iRacing at this resolution. Road Racing on triple screens uses a lot of CPU and Intel chips are simply faster. If you want the best frame rates, buy Intel for now. That said, I'm not about to buy a new motherboard, RAM and processor. So, I bought a new processor. An AMD Phenom x4 BE 970. This is a quad core chip at 3.5Ghz with 6MB L3 cache. It just drops in to my ASUS M4A785G motherboard and I like that about AMD a lot.

My Nvidia GT240/Matrox Triplehead2go/AMD 620 rig was plenty fast frame wise BTW if you're happy at 3x1280x1024.

I bought it at newegg for 190. The AMD 6 core chip is 230 but only clocks at 3.2Ghz so I figured i'm better off with faster cores and fewer of them since iRacing only uses 2 cores right now, maybe 3 cores in an upcoming release according to rumors.

The chip should arrive this week and I'll post the numbers.

iRacing triple screen with ATI 6870 card working

I finally got this all working. My current setup is

ASUS 785G AM2+ motherboard with 4GB RAM

AMD Phenom 620 quad core 2.6GHz processor

900W Powersupply (upgrade from 500W for 6870)

My 6870 has a mini displayport and two DVI connectors. I have monitors connected to the DVI connections and I bought a mini displayport to displayport adapter. My ATI certified displayport to DVI single link adapter is connected to that and I have a DVI to HDMI cable to the third monitor.

I had to create a group of 3x1 in the ATI software. Simply extending my desktop to all 3 monitors did not work. It works for Windows but iRacing still only saw one monitor. Creating the group of 3 monitors allowed iRacing to see the large display 57xx x 1080.

Frame rate wise, I'm on class 2 with cockpit mirrors enabled and I get between 35 and 60fps which is acceptable for me. This card cannot drive all 3 monitors in maxed out mode fast. Class 1 settings were about 30fps but higher sometimes depending on the track. Lime Rock is about 60fps now.

I tried the Apple mini displayport to DVI connector and it does not work. You need the ATI certified 30 buck one to get it all to work.

Upgrading my iRacing sim racing rig

I'm using an iRacing sim racing rig to get a lot of lap time lately. I didn't manage to get to the track at all this year in my spec 944 race car mainly because running a marathon was my priority. I did use my iRacing rig which if you haven't tried it is a very good substitute for learning tracks and so on.

My current system is a PC running Windows 7 64 bit. It has a quad core AMD Phenom 620 CPU, 4GB of RAM and a NVidia GT240 graphics card. The card drives a matrox triplehead2go digital edition that in turn is connected to 3 x 24 inch monitors. I have a logitech g27 wheel, fanatec clubsport pedals with brake pedal load sensor and a nice chair. It's basically a dedicated iRacing setup.

A problem so far is that my monitors are 1080p monitors. But, the system can only drive them at 1280 x 1024 rather than their native 1920 x 1080 resolution. This seems to be a limitation of the matrox 'splitter'. This results in the monitor stretching the picture to fill the screen and I get a lot of artifacts on the screen. A native picture would be a lot clearer and have a lot more detail, more pixels.

I purchased a more powerful graphics card this week, an ATI 6870. The 6870 has ATIs eyefinity technology which means one video card can directly drive 3 monitors. This means I don't need the matrox and also means I can finally drive the monitors at their native resolution. The only gotcha with the 6870 is that one of the three monitors must be a displayport monitor. Displayport is a new standard for connecting monitors to computers. None of my existing monitors have a displayport connector. They are all DVI or HDMI.

You can purchased another newer monitor or get a displayport to dvi convertor. These were expensive, about a 100 bucks and needed to be powered also. Lately, ATI is supporting a new type of non powered or passive connector. These are 30 bucks and I bought one of these.

So, the new gear is arriving from newegg on Thursday so maybe I'll have an update then.

Getting tempted again, a 2004/5 Porsche 996 GT3...

Maybe, it's just the weather but the Porsche 996 GT3s are looking very attractive. They look about 48-55k right now for a 2004 and would be much more reliable than the usual 996 cars given the GT3's have 'proper' engines.

There seems to be a good selection of cars available. I'd consider one or a Corvette Grand Sport which would be a very nice car also and would be new with a warranty.

New DFI engines, makes a 997 worth owning again?

The new 2010 DFI engined 997s look like they might actually hold up to some speed work. They still don't have a proper dry sump but it looks like Porsche are definitely improving the oiling to improve things over the old M96/M97 engines. Time will tell.

Porsche 997 PDK clutch replacement cost

I just got a quote from a Porsche dealer on this. The parts are around 950 bucks and installed, a new PDK clutch will cost 1900 dollars. This doesn't seem so bad given it's about or less than the cost of a new clutch on a manual car and you gotta figure a PDK clutch will outlast a conventional one given the computer does the shifting. It'll be interesting to see whether it outlasts a manual clutch in practise.

Driver improving

I went to MAM yesterday, my first time since 2006 in my old Porsche 996 and happily, I'm now quicker in a car with half the horsepower. Pretty cool. Here's a comparison of two sessions, you can see that today I'm a lot faster through the turns and using more of the tire G's around turns. I'm throttle steering the car through most turns now (rotating the car by moving weight to and fro using the throttle). Anyway, it's nice to see an improvement from buying a car which costs about the same as a set of rims, tires and coilovers for the 996... Pink is lateral Gs for the 944 sp1, red is the GPS mph.

Last track weekend of the year for me

and also the second! Did nothing this year except for Bondurants 4 day school and a PCA weekend. Very sad to look at the race car in the garage building up dust. But, two days of open track on Sat/Sun this week so thats cool. May be raining on Sunday a little, we'll see.

Do I want another fast car? No, I want a ...

I'm always thinking of buying another sports car to replace the 996. The Vette is actually top of my list now. It's more car than anybody needs on the road, does a Porsche handle better, yep, but the Vette is half the price and apart from on a race track with a better driver than me (and I'm crap but still better than most untrained drivers on the road, it's all relative...), people won't tell the difference.

Trouble is, I don't want a Vette. I want a Vette with a race suspension, maybe a racing seat, harnesses, etc, i.e. I don't want a vette or any other sports car, I want a race car.

And thats the problem. Almost every normal sports car is compromised. You can buy a 911 but straight away, you upgrade the seats, maybe springs or put coil overs on it, you get the picture, you don't want a Sports car, you want a race car.

And once you get the race car, you can't drive it on the public roads anyway without going to jail so whats the point. Either buy the stock car and drive it around like an SUV or stick with the SUV and buy a track only race car which is what the smart money does.

So, I drive my GMC 2500 pickup on public roads, still thinking about buying a sports car...

Rare yellow uk 944 turbo?

My brother just bought this 1987 Porsche 944 turbo in yellow with cruise control which is supposed to be rare on a uk model.