Is my GPU/CPU non optimised ?

[IhazHedont]

Hey guys, first post here.

 

I think that I'm a bit misleaded regarding the so called "bottleneck". My rig is running with a GTX780, and an i7 950 (base clock), 12Go ram.

 

I saw some videos on youtube (including the one from Linus) and another one coming from Jay2cents, and I'm a bit confused.

 

In the Jay video, he makes some tests,trying to bottleneck his GPU by downclocking his CPU. And when he does it, he shows up the MSI curves, and his GPU is running at 60% because of its CPU.

 

The thing is, my GPU runs also at 60% on some games, but I have good framerates. Does this mean that the game didn't require the GPU runs over 90% to work well ?

 

On the other hand, a recent game like FarCry 4 actually needs 98% of my GPU to run.

 

That's why I don't really understand how to "visualize" the bottleneck.

 

Is it possible that my cpu, (which is now old) bottleneck a gtx 780 ? What if I decide to get another 780 for SLI ?

 

Thanks in advance !

[lani100]

Hey guys, first post here.

 

I think that I'm a bit misleaded regarding the so called "bottleneck". My rig is running with a GTX780, and an i7 950 (base clock), 12Go ram.

 

I saw some videos on youtube (including the one from Linus) and another one coming from Jay2cents, and I'm a bit confused.

 

In the Jay video, he makes some tests,trying to bottleneck his GPU by downclocking his CPU. And when he does it, he shows up the MSI curves, and his GPU is running at 60% because of its CPU.

 

The thing is, my GPU runs also at 60% on some games, but I have good framerates. Does this mean that the game didn't require the GPU runs over 90% to work well ?

 

On the other hand, a recent game like FarCry 4 actually needs 98% of my GPU to run.

 

That's why I don't really understand how to "visualize" the bottleneck.

 

Is it possible that my cpu, (which is now old) bottleneck a gtx 780 ? What if I decide to get another 780 for SLI ?

 

Thanks in advance !

There shouldn't be a bottleneck maybe a tiny little bit but these problems can be solved with a small overclock.

[H4X3R]

No bottleneck should be present, but you can OC your CPU and you'll most likely get a boost in games.

[Johannes_Lazor]

It depedns on the game, You can lower the shadows or push more AA and resolutions to balance the load,
Or OC.

[SkilledRebuilds]

It really does depend on how the game handles multiple cpu's.

[IhazHedont]

Thanks for the answers guys ! I'll OC my CPU to reach 4GHz, it seems to be easy with this one.

[D2ultima]

Thanks for the answers guys ! I'll OC my CPU to reach 4GHz, it seems to be easy with this one.

You actually have a bit of a bottleneck, which is to say that "if you put in a haswell i7 you would see much improved framerates in some games", but that's a different kind of bottleneck than what you're thinking about. Let me explain the basics.

 

Basically, a CPU renders frames very lightly (think of a basic outline) and sends it to the GPU to fill in with colour/textures/etc. There are three things that affect the CPU's ability to do this:

1 - Clock Speed. The higher it gets, the more your CPU can do per second etc. Increasing this is the quickest way to relieve a bottleneck, but also the least effective.

2 - How many cores the program uses. This is not something you can easily fix. This is usually engine-side and program-specific. If a game uses 1 core alone, having a 8-core, 16-thread i7-5960X @ 4GHz will be the same as having a 2-core, 4-thread i3-4130 @ 4GHz (not saying that you can set a core i3 to 4GHz, but just making an example). If a dev recognizes a specific core-based bottleneck and patches it out (for example, I believe it's Far Cry 4 that's currently using 100% of everyone's "core 3" on i7 CPUs... if they spread the load out more evenly via a patch, less framedrops etc will happen).

3 - The instructions per clock (IPC) of a CPU. An i7-4770K @ 3.5GHz beats an AMD FX-8350 @ 4.4GHz in almost every game out there... the reason is because AMD's CPUs have very low IPCs. You need to clock them much higher for the same effect. This is why Haswell is faster than Ivy Bridge and Ivy Bridge is faster than Sandy Bridge etc; each new architecture boosts the IPC a little bit.

 

If you're using vSync or the game has a built-in FPS cap (like Dark Souls 2 at 60fps) then your GPU will simply render only as much as needed, and its utilization will stay low.

 

Also, some games just don't use GPUs very well... like Terraria. Terraria will have CPU power and GPU power to spare, but simply not go above framerate X easily. It's just the game's coding. If others have difficulty going above a certain framerate in a game like you do, then that's likely the game.

 

Lastly, your i7-950 isn't all that weak, but it isn't all that strong anymore either. A sandy bridge i7 will spank it silly, and haswell is a massive upgrade over it. It's up to you if you want to upgrade now or later or at all though. The IPC of that architecture isn't very high is all.

 

Next, this is where finding a CPU bottleneck gets tricky. See, some games are coded to use 2 cores alone. But instead of taking 2 cores and ramping it up to 100% (which is inefficient and heat-inducing), devs usually code it to spread the load across your 4 cores. If you checked with an overlay or task manager though, you'd likely find you don't go above 50% CPU usage in many games. So watch for this... if your FPS is below 60 and your CPU is capping out somewhere between 50% and 60%, then you can look for benchmarks with your GPU online and see if others have higher FPS. If they do, it's a CPU bottleneck.

 

The next, MUCH more uncommon type of bottleneck is where the CPU will hit 85%-90% and then your utilization will begin dropping. This happened to me in exactly one instance: I had to go in Crysis 3, OC my 780Ms, play on max graphics, then get to the field where you avoid the huge supposedly insta-kill railgun thing. My CPU started hitting 90% due to the long view distance (too much to render) and my GPUs started going down to 66-70% utilization. That's the second kind of CPU bottleneck you can notice, but that one is easiest as you'll flat out see that your CPU is struggling like crazy.

 

I put a whole lot of info here, but I hope it helps.

[IhazHedont]

Well thank you for the explanation, I was looking for something like that.

 

I was planning to upgrade my rig, but you know, I believe it's not the good time (like for the screens with 4k, G sync and so on), because DDR4 just came out, and I it would be sad to upgrade my rig with a DDR3 MB/CPU.

 

For instance I checked the benchmarks with FarCry 4, and it's actually well performing, because i'm very close to the tests results.

 

But in the end yes, CPU upgrade is in my mind, just awaiting the "democratization" of the new DDR4 products.

 

Regarding the current products, and since I might go for a GTX780 SLI, which CPU would you recommend to me ?

 

Thanks again !