i5 on the way

[gizmo71]

Ordered myself a Core i5 670 (3.46GHz), 4GB DDR3 and GigaByte mobo for delivery Monday. Will probably take me all week to build and tune properly; hopefully the end result will allow me to run iRacing at 3*FullHD resolution with each screen rendered seperately, instead of as a single giant image - that allows it to get the perspective right across all three, which makes placing the car at the edges of the track much easier.

My E8400 struggles a bit with that - by my reckoning an i5 should be 10% faster clock for clock, so I should be looking at a total speed improvement of around 26% - not earth shattering, but it should be enough for my purposes.

The real question... will iRacing (which uses two threads) run better or worse with hyperthreading turned on?

<Banzai> Place bets now! </Banzai>

[Rik]

We await the results with interest, Giz.

[Technical Ben]

Does not having a better GPU provide the real boost? I mean, as your going pixel based game play here, your limiting factor seems to be the GPU speed. But then I am biased for ATI and their 4870 or 5850 and a Eyefinity. 

[gizmo71]

Does not having a better GPU provide the real boost? I mean, as your going pixel based game play here, your limiting factor seems to be the GPU speed. But then I am biased for ATI and their 4870 or 5850 and a Eyefinity. 

It's true for most games, but for the more serious racing simulators the CPU is usually the bottleneck - in my case (E8400 with a 5870 pumping out 3*FullHD in Eyefinity) it's very clear (and entirely expected) that the CPU is the bottleneck.

Pushing pixels is important in games but in proper simulations, physics is more important - and more resource hungry.

[mrapoc]

all of that for one game? 

must have you hooked

[Rik]

Hi Sam.

[mrapoc]

Ohhh hello there   

iv been lurking for a while, didnt get on much over xmas/new year due to having pig flu  and other than that been mega busy!

[Rik]

I've managed to avoid it, Sam, having been given the jab. Last time I had one, I ended up getting the flu instead.

[gizmo71]

all of that for one game? 

must have you hooked

iRacing's the mother of all racing sims right now - though GTR2 and GT Legends will also benefit.

[gizmo71]

Well the answer to the hyperthreading question was...
iRacing runs better with it turned off. Lots of stutters with it on. I guessed that would be the case.

I have to say, the i5 at 3.46GHz is barely any quicker than the E8400 at 3GHz - I didn't expect a miracle but I'm a bit disappointed that the difference isn't more noticable. I'll do some controlled overclocking tomorrow and see what I can get to with the stock cooler.

[Glenn]

Dave,

Would you recommend an i7 system over the i5? I had a brief trial with iracing last week at a friends house, and liked what I saw, so, I may upgrade.

[gizmo71]

Would you recommend an i7 system over the i5? I had a brief trial with iracing last week at a friends house, and liked what I saw, so, I may upgrade.

I think it's impossible to answer that without know what you're going to run on it...

[Glenn]

iRacing is the plan, I currently have a E6750 with 4Gb ram running via a Nivida 8800GT connected to a Matrox TH2G adaptor, with 3 screens. The graphics card would be upgraded to an eyefinity capable card.

[gizmo71]

That's a tough call right now. You'll get more obvious benefit going to something like an i5-660 or i5-670 compared to where you are now, but even with overclocking you won't be able to run three screens in triple render mode at full detail on any current CPU.

Until the new sound processing code is released towards the end of this year iRacing only uses two threads, so right now an i7 really does buy you anything over an i5 except more overclockability. Even when the new sound code arrives and it uses three threads, the bulk of load will still be in graphics processing if you're triple rendering (which I presume you'll want to do, unless your three screens and in a single plane) so it won't really get you much of an improvement.

Unless you go down the much more expensive Xeon route, there's no way to get a CPU (i5 or i7) with four cores that has the same clock speeds as the dual core plus hyperthreading chips mentioned above. That'll hurt iRacing performance and you could easily end up not making a significant step forward from where you are now.

Out of interest, what sort of resolution and level of detail are you using, and what frame rates are you getting?

[Technical Ben]

I forgot which graphics card you said you have Gizmo? But I am certain that most games are 80-90% down to your graphics card, the other 10-20% is the CPU. Especially on a three screen setup, as you need the extra GPU cycles for pixel crunching. None of the pixel/graphics goes through the CPU, only a tiny amount of calculations for the game engine. And as it racing, it's just A-B and lap times. Do you have a dual card ATI with triplehead? I should really search for that post.

[gizmo71]

I forgot which graphics card you said you have Gizmo? But I am certain that most games are 80-90% down to your graphics card, the other 10-20% is the CPU.

Most games, yes, but not the hardcore racing sims, which are mostly physics bound (on the CPU). iRacing in particular is still stuck on what is effectively a decade-plus old graphics engine (it dates back to Grand Prix Legends, released around 1998) and is mired back in DirectX 7 or so. I've got a 5870, but only because the Eyefinity enables me to run three screens without TH2Go or SoftTH mucking about.

[Technical Ben]

Sorry, I just saw, you posted a reply already! I must have been tired last night.  
A 5870 is the king of cards right now, so good one! I guess Iracing need to look at optimising the code.
Because your system should be able to cope really. I can see why a few people went down the dedicated Physics card route a few years back. Some people still install a second GFX card and run it as a physics card. Although only a handful of games support it, they have parallel processing, so they storm through the code.

Hope you get it sorted!

[Glenn]

I installed iRacing on my PC on Monday, everytime I try running it, the screen freezes after about 1 minute, it's running on a E6750, with 4Gb ram and a 8800GT graphics card, all on Windows 7 64bit.

[Technical Ben]

Hmmm. That kind of crash could be no end of things. Graphics drivers, sound drivers, overheating, ram problems...

[gizmo71]

If I had to guess I'd say your graphics card is overheating. The 8800s have a terrible reputation - I had one that died through overheating, despite extra cooling placed over it. If it runs normally when not doing GPU-intensive stuff that would support that theory, although a failing PSU might produce the same result.

[Glenn]

It all works fine with rfactor

[zappaDPJ]

We had someone with the same issue on one of our forums. It was a long running thread and a lot of things were tried including, updating graphics card drivers, extra cooling and changing the running environment in terms of graphics quality. If memory serves, he found a solution by fixing the game frame rate to something other than what it had been set at. The forums are currently off-line and undergoing a major update but as soon as I can get them brought up again I'll go check the thread.

[Glenn]

I may do a complete reinstall, using Win 7 32 bit or XP, only installing iracing, then see what happens.

[gizmo71]

It all works fine with rfactor

Probably best to ask over on the iRacing forums if you haven't already...