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Solved Forum question

Started by McDohl | | 24 answers
Which is bottlenecking which in this scenario?
Example:
GPU usage: 100%
CPU usage: 65%


My assumption here is that the GPU can't keep up with the CPU. Is this correct or incorrect?

Or can a GPU be bottlenecked by a CPU load that isn't at 100%? (Also RAM isn't maxed)
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September 16, 2014 9:27:04 PM

clutchc said:
McDohl said:


I went ahead and purchased the FX 6300, installed it...

???
You installed the FX-6300 in what?

In the m3a78-em.

I'm just messing with ya haha. I got a GA-78LMT-USB3 motherboard and a ram stick as well.
a c 424 à CPUs
September 16, 2014 6:20:53 PM

McDohl said:


I went ahead and purchased the FX 6300, installed it...

???
You installed the FX-6300 in what?
September 16, 2014 3:57:30 PM

clutchc said:
How the heck did you get a GTX750 Ti to be recognized on that old Asus M3A78-EM MB? The new Maxwell GPU is usually a no-go for old MBs. Even with their most recent BIOS version.

As the synthetic benchmark points out, the R9-270 should be and usually is a considerably faster card than the GTX 750 TI. I have both cards on my shelf right now and have tested with both. The 270 always beats the 750 Ti.
But I can't explain the difference you report between CPU/GPU usage in that game you linked to. The CPU should have been at a higher usage with the R9-270 than the 750 Ti. (??) How did the frame rates compare? Possibly that game was optimized for Nvidia drivers? Seems like a big difference, but that is all I can think of.

Are you positive all settings were the same with both cards? Nivdia may have had PhysX enabled, where AMD didn't because it has no PhysX. As a result, it had to do the CPU physics with no added help.

If you do decide to go for a CPU upgrade, I really suggest you save for a new build. The old, slow DDR2 and the way obsolete AM2/AM2+ socket is going to always hold you back when it comes to CPU selection. And the selection will be limited to very used CPUs.

Lmao, I have no idea man. I just plugged it in and it worked. I was surprised to find that the port was PCIE 2.0 and not 1.0.

It didn't make sense to me either, the R9 270 is obviously better than the 750 ti. It doesn't say whether it's optimized with Nvidia or AMD, but I think it has to be Nvidia, that's the only way it makes sense.

I went ahead and purchased the FX 6300, installed it, and ran the 6300+750 ti to these results: http://oi58.tinypic.com/2ce6fcw.jpg A much more stable FPS, and significantly higher.

In Sleeping Dogs it doesn't reach framerates as high as the Phenom 9550+270, but it's *far* more stable and playable: http://oi59.tinypic.com/317a900.jpg

Thanks for all the help. I'm much more happy with this route than keeping the old Phenom.
a c 424 à CPUs
September 16, 2014 12:42:25 PM

How the heck did you get a GTX750 Ti to be recognized on that old Asus M3A78-EM MB? The new Maxwell GPU is usually a no-go for old MBs. Even with their most recent BIOS version.

As the synthetic benchmark points out, the R9-270 should be and usually is a considerably faster card than the GTX 750 TI. I have both cards on my shelf right now and have tested with both. The 270 always beats the 750 Ti.
But I can't explain the difference you report between CPU/GPU usage in that game you linked to. The CPU should have been at a higher usage with the R9-270 than the 750 Ti. (??) How did the frame rates compare? Possibly that game was optimized for Nvidia drivers? Seems like a big difference, but that is all I can think of.

Are you positive all settings were the same with both cards? Nivdia may have had PhysX enabled, where AMD didn't because it has no PhysX. As a result, it had to do the CPU physics with no added help.

If you do decide to go for a CPU upgrade, I really suggest you save for a new build. The old, slow DDR2 and the way obsolete AM2/AM2+ socket is going to always hold you back when it comes to CPU selection. And the selection will be limited to very used CPUs.
September 15, 2014 9:13:27 PM

clutchc said:
The HD 7950 is indeed the R9-280. The "R9-280" is just re-badged*. In fact, my above-mentioned R9-280 shows up as an HD 7950 in most apps. Again, more than the older Phenom/MB/DDR2 could keep up with. I would expect CPU usage to be 100% and the card at less than that. And you don't want your CPU cranking away at 100%. It has other work to do... and the stock cooler (?) will sound like a turbine.

You could also consider the GTX 760. It falls in the same category as the R9-270/270X. But keep in mind, most of these close matches between cards are almost impossible to tell the difference in actual gaming. Here is another chart for you. It is a gaming gfx card hierarchy chart that places the cards in tiers. As the article states, you would have to move at least 3 tiers to see enough improvement to make the price difference worth while.
http://www.tomshardware.com/reviews/gaming-graphics-car...

* The reference HD 7950 is a bit lower performance than the R9-280 due to slightly lower clock speed. But most manufacturers have them at the same speed as the 280.

That's an extremely helpful chart! Damn, that would've saved me a *lot* of time. I'm relatively new to the PC gaming domain, so. But that makes sense, I think you're absolutely right about it not being able to handle the 7950.

I swapped the 270 out for the 750ti, ran it through AC4/SD/NBA2k and it was quite revealing.

http://oi60.tinypic.com/316q79h.jpg

As you can see, CPU is maxed. Three cores hit 100% at once, actually. This is very strange, though. With the 750ti it used only about 50% of the GPU resources, but *far* more CPU resources. In the end the FPS was far more stable, and far superior to the 270. With the 270 it was reversed: around 50% CPU resources, and 98% GPU resources. I don't understand that...

I'm starting to think upgrading the CPU may be the best bet. And that these combined scores are too similar for both cards not to be bottlenecked (Maybe mobo, ram, cpu):

r9 270:
http://www.3dmark.com/3dm/4054907

750ti
http://www.3dmark.com/3dm/4058934

Best solution chosen by McDohl

a c 424 à CPUs
September 15, 2014 8:02:15 PM

The HD 7950 is indeed the R9-280. The "R9-280" is just re-badged*. In fact, my above-mentioned R9-280 shows up as an HD 7950 in most apps. Again, more than the older Phenom/MB/DDR2 could keep up with. I would expect CPU usage to be 100% and the card at less than that. And you don't want your CPU cranking away at 100%. It has other work to do... and the stock cooler (?) will sound like a turbine.

You could also consider the GTX 760. It falls in the same category as the R9-270/270X. But keep in mind, most of these close matches between cards are almost impossible to tell the difference in actual gaming. Here is another chart for you. It is a gaming gfx card hierarchy chart that places the cards in tiers. As the article states, you would have to move at least 3 tiers to see enough improvement to make the price difference worth while.
http://www.tomshardware.com/reviews/gaming-graphics-car...

* The reference HD 7950 is a bit lower performance than the R9-280 due to slightly lower clock speed. But most manufacturers have them at the same speed as the 280.
September 15, 2014 7:42:31 PM

clutchc said:
It's hard to get much more than a few-megahertz bump in BCLK frequency w/o an unlocked CPU clock multiplier. It would help, yes. But not enough to warrant an R9-280X... in my opinion. I doubt my Phenom II X4 965BE at 4.0GHz could keep up with an R9-280X. And it is on a late AM3 MB with DDR3 1600MHz RAM.
If you have money to burn and want to try it out, go for it. But I doubt you'd get any better gaming performance than with the R9-270X. Btw, there's a nice jump in performance between the 270 and 270X. http://www.anandtech.com/bench/product/1080?vs=1043

You're absolutely right, I forgot about that. Do you think an HD 7950 would be pushing it? I think it's slightly better than a 270x, basically a normal r9 280. Thanks for providing that link! I didn't know the difference between the 270 and 270x would be that considerable. If you don't think a 7950 would work I'll likely go the 270x route.
a c 424 à CPUs
September 15, 2014 5:25:00 PM

It's hard to get much more than a few-megahertz bump in BCLK frequency w/o an unlocked CPU clock multiplier. It would help, yes. But not enough to warrant an R9-280X... in my opinion. I doubt my Phenom II X4 965BE at 4.0GHz could keep up with an R9-280X. And it is on a late AM3 MB with DDR3 1600MHz RAM.
If you have money to burn and want to try it out, go for it. But I doubt you'd get any better gaming performance than with the R9-270X. Btw, there's a nice jump in performance between the 270 and 270X. http://www.anandtech.com/bench/product/1080?vs=1043
September 15, 2014 3:56:25 PM

clutchc said:
In that screen shot, one core was hitting 70%. Getting up there. But that is still good. I don't know if I'd push my luck with a jump to a R9-280X. Then you would definitely have some bottle neck. In between what you have now and the 280X are two other cards; the R9-270X, and 280. I think you may be at the sweet spot for CPU/GPU/MB now... or maybe with an R9-270X. I imagine you still have an older AM2 or AM2+ MB with DDR2 1066MHz (or lower) system RAM.

Are you getting stutter or lag when you game? Other parts of the system may be the cause if you are. The memory may be bottle-necking. Or the Hyper Transport speed.

Do you think I could push towards 280x if I were to overclock? I haven't touched that yet, currently at 2.2ghz and I think I could get to 2.7-3ghz.

Great points. I don't on Sleeping Dogs, but I DO have quite a bit of stuttering on AC4, then again it's AC4. I may get BF4 or Metro 2033 to test that out. Thanks for the input so far, you've been very helpful.
a c 424 à CPUs
September 15, 2014 3:39:11 PM

In that screen shot, one core was hitting 70%. Getting up there. But that is still good. I don't know if I'd push my luck with a jump to a R9-280X. Then you would definitely have some bottle neck. In between what you have now and the 280X are two other cards; the R9-270X, and 280. I think you may be at the sweet spot for CPU/GPU/MB now... or maybe with an R9-270X. I imagine you still have an older AM2 or AM2+ MB with DDR2 1066MHz (or lower) system RAM.

Are you getting stutter or lag when you game? Other parts of the system may be the cause if you are. The memory may be bottle-necking. Or the Hyper Transport speed.

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