Tom's Hardware: CPU/GPU Bottlenecks

[RussianSensation]

Actually you can look at the article and conclude that CPU speed/core count isn't particularly important for a GTX 460 class video card. That seems like valuable information to me.

It shows that speed/core count beyond 2 isn't particularly important when you are looking at a Core i5 8mb cache CPU with a GTX460 768mb. It doesn't tell us anything about how a 2.0-4.0ghz C2D 2mb/3mb/6mb /C2Q 65nm/45nm or Phenom I or II systems would do.

Also some of their findings that CPU clock speed/Core count are not important are contradictory to their own findings. Even at only 1280x1024, Phenom II @ 2.5ghz system is borderline unplayable in SC2.

 

[blastingcap]

It shows that speed/core count isn't particularly important when you are looking at a Core i5 8mb cache CPU. It tells us nothing about how a 2.0-4.0ghz C2D 2mb/3mb/6mb /C2Q 65nm/45nm or Phenom I or II systems would do.

Should we petition Anand or Ryan or someone else to do something like this, but on a larger scale with more resolutions, settings, and GPUs tested?

http://www.anandtech.com/show/3937/...thlon-ii-cpus-balance-price-and-performance/5

 

[RussianSensation]

Should we petition Anand or Ryan or someone else to do something like this, but on a larger scale with more resolutions, settings, and GPUs tested?

http://www.anandtech.com/show/3937/...thlon-ii-cpus-balance-price-and-performance/5

Ya, AT should definitely do a proper CPU limitations article.

I mean who is going to be playing BF:BC2 @ 35 pfs, Just Cause 2 @ 35 fps, Metro 2033 @ 16 fps, STALKER: CoP @ 33 fps?? This article basically took a $130 videocard, hammered it with tessellation and 4/8AA at 1920x1200 and concluded that obviously CPU performance doesn't matter. I guess they forgot that some people don't play games at 16-35 fps @ 8AA.

 

[Patrick Wolf]

It shows that speed/core count beyond 2 isn't particularly important when you are looking at a Core i5 8mb cache CPU with a GTX460 768mb. It doesn't tell us anything about how a 2.0-4.0ghz C2D 2mb/3mb/6mb /C2Q 65nm/45nm or Phenom I or II systems would do.

Also some of their findings that CPU clock speed/Core count are not important are contradictory to their own findings. Even at only 1280x1024, Phenom II @ 2.5ghz system is borderline unplayable in SC2.

Perhaps they decided against testing AMD cpu's as the general consensus is that if you're serious about gaming you would just go Intel since they almost always perform better.

 

[AtenRa]

Perhaps they decided against testing AMD cpu's as the genreal consensus is that if you're serious about gaming you would just go Intel as they generally perform better.

In high resolution of 1920 and up, both AMD and Intel CPUs perform the same most of the time.

 

[RussianSensation]

In high resolution of 1920 and up, both AMD and Intel CPUs perform the same most of the time.

Yes, once you are at 1920x1200+, you are basically GPU limited. The problem is in some games you can't crank 1920x1200 or AA. So you naturally remove AA and lower resolution to get playable settings. Then CPU becomes a factor.

BitTech.net - Crysis - 1680x1050 0AA
Core i7 930 @ 4.3ghz + HD5870 = 58 avg (+35&#37 / 39 min (+63%)
AMD 1055T @ 3.2ghz + HD5870 = 43 avg / 24 min

Of course you can crank 8AA and you'll probably get 30-35 fps average on both systems with 20 mins, easily arriving at a GPU bottleneck. What if someone prefers to play at 60 fps avg/0AA over 30-40 fps/8AA with 20 mins?

On one hand I applaud Tom for showing to gamers once again that one part of their system they shouldn't skimp on is the GPU. On the other hand, the author automatically assumes that eye-candy is more important for gamers over smooth constant framerates by testing some very intensive games at 35 fps @ 8AA, and thus suggesting no CPU limitation exists.

 

[3DVagabond]

1. Wouldn't play any smoother. The 480 would just net you more FPS, unless the game has a cap.
2. E8200 + 480 is faster, unless the game benefits drastically from 3+ cores which is very unlikely.
3. Depends on the game. A better question would be, at what point will developers start optimizing their engines for quad/hex core CPU's? Xbox 3, PS4 era maybe?

This is pretty much exactly as I see it as well. I've seen threads though where people ask for advise on upgrading their cards and all they get is, "But a new system. Yours is crap and will bottleneck that GPU". Now, that's a bit dramatized and very abbreviated, but not to far off from how it goes. This is probably the whole reason for Tom's doing the article.

 

[crisium]

Perhaps they decided against testing AMD cpu's as the general consensus is that if you're serious about gaming you would just go Intel since they almost always perform better.

You can be serious about gaming but have a low or medium budget. For some of the price ranges below the i5 750, AMD has a better priceerformance ratio. And they are important to test for the reasons discussed: CPU vs GPU.

Consider this scenario. Your budget for combined CPU + GPU is $300. Let's assume everything else is budgeted out and the AMD and Intel motherboards cost the same. What's the best gaming system you can build for a CPU+GPU $300 combo? You could get an i5 750 + a GTS 250 512mb. Or you could get an Athlon II X3 445 (3.1GHz triple core) + a GTX 460 1GB.

See that's a tough cookie. AMD also presents the options of dual core, triple core, or quad core. Even multi threaded games rarely show any gain from 3 to 4 cores. A discussion of CPU cores should really include AMD.

That's what I want to see in an article in addition to core scaling on Core i5/i7 and Phenom/Athlon II. Different budget builds for CPU+GPU. A $300 build like the one I suggested, going on the extremes of a high priced CPU vs GPU.

What about a $200 low budget build scenario with a Athlon II X2 250 (3GHz dual) and a GTS 450 / Radeon 5770 vs an Athlon X4 640 (3GHz quad) and a GTS 250 / Radeon 4850?

Or a budget of $455 makes you decide between an i7 870 and a GTX 460 768MB vs an i5 750 and a Radeon 5850?

 

[Patrick Wolf]

You can be serious about gaming but have a low or medium budget. For some of the price ranges below the i5 750, AMD has a better priceerformance ratio. And they are important to test for the reasons discussed: CPU vs GPU.

I should've said serious about eye candy, which means nothing without good performance. But I see your point and it's something they should've included.

 

[SlowSpyder]

I game at 1920x1200 and use AA. I'll take my Phenom 940 and a 5870 over an i7 @ 4GHz and a 5830 rig. I think it has been fairly well known for a while that at resolutions we actually game at a bigger GPU will generally give you more benefit than more CPU in most cases (assuming you're running modern hardware, not a Pentium 3 for example).

 

[MJinZ]

• Part 1: http://www.tomshardware.com/reviews/game-performance-bottleneck,2737.html

• Part 2: http://www.tomshardware.com/reviews/game-performance-bottleneck,2738.html

Aside from known outliers like GTA4 and Dragon Age, in the vast majority of cases two cores are virtually as fast as four cores, and the GXT460 bottlenecks performance.

Therefore, in that selection of games at those settings, a dual-core + GTX480 would provide far better performance overall than a quad-core + GTX460, indicating yet again that the graphics card is the most important part of the gaming equation.

This is what I’ve been saying for quite some time, and mirrors my own findings.

I ran Dragon Age with a 4.2ghz Core i7 and a GTX 480 @ 1920x1200 with max settings, but if I went anywhere near 8x Antialiasing, the game would choke.

If I had to run with a dual core, I think I would just throw it away in disgust.

 

[toyota]

I ran Dragon Age with a 4.2ghz Core i7 and a GTX 480 @ 1920x1200 with max settings, but if I went anywhere near 8x Antialiasing, the game would choke.

If I had to run with a dual core, I think I would just throw it away in disgust.

what? Dragon Age does love quads but a fast dual core cpu is plenty for that game to be playable. if your game was choking with AA then that has nothing to do with the cpu anyway.

 

[blastingcap]

Consider this scenario. Your budget for combined CPU + GPU is $300. Let's assume everything else is budgeted out and the AMD and Intel motherboards cost the same. What's the best gaming system you can build for a CPU+GPU $300 combo? You could get an i5 750 + a GTS 250 512mb. Or you could get an Athlon II X3 445 (3.1GHz triple core) + a GTX 460 1GB.

Huh? You can get a Phenom II X4 955 for ~$140-150 and oc it, and have enough money left over for a GTX460-768MB at ~$140-160 (depending on how you feel about rebates).

But I'd definitely go for a i5 760 and get a HD5770 which is approximately the same price and better-performing than the GTS 250, then swap out the GPU later as needed. It's a lot easier to swap out GPUs than CPUs.

 

[MJinZ]

what? a fast dual core cpu is plenty for that game to be playable. if your game was choking with AA then that has nothing to do with the cpu anyway.

The game was coded POS basically filled with memory leaks.

It still choked every 5 seconds since you have to change camera angles and perspectives all the time in environment and combat.

 

[Patrick Wolf]

I ran Dragon Age with a 4.2ghz Core i7 and a GTX 480 @ 1920x1200 with max settings, but if I went anywhere near 8x Antialiasing, the game would choke.

If I had to run with a dual core, I think I would just throw it away in disgust.

Choke how so? More frequent drops to unfavorable framerates? Cause the article contradicts what you're saying (unless they didn't max out settings, nor did they give minimums for that game which isn't always representative of actual smoothness while playing).

 

[MJinZ]

Choke how so? More frequent drops to unfavorable framerates? Cause the article contradicts what you're saying (unless they didn't max out settings, nor did they give minimums for that game which isn't always representative of actual smoothness while playing).

It can not transition different perspectives.

 

[cusideabelincoln]

It shows that speed/core count beyond 2 isn't particularly important when you are looking at a Core i5 8mb cache CPU with a GTX460 768mb. It doesn't tell us anything about how a 2.0-4.0ghz C2D 2mb/3mb/6mb /C2Q 65nm/45nm or Phenom I or II systems would do.

Also some of their findings that CPU clock speed/Core count are not important are contradictory to their own findings. Even at only 1280x1024, Phenom II @ 2.5ghz system is borderline unplayable in SC2.

It's still informative. I've already addressed the issue of just disabling cores earlier.

You have a beef with the analysis of the article, but the data looks solid to me. Don't have a beef with the data.

 

[RussianSensation]

You have a beef with the analysis of the article, but the data looks solid to me. Don't have a beef with the data.

I am not so concerned with the data as I am with the the dangerous advice that can come out of it. I just don't want to see someone looking to build a system to last 2-3 years go out and buy a Core i3-560 3.33ghz ($150) + GTX460 1GB ($200) over a Core i5 750/1055T ($200) + GTX460 768mb ($150) because of that article. This is exactly the type of advice I fear because it will result in the person upgrading both the GPU and the CPU 2 years from now. The i3 system will be basically worthless while a 3.8ghz+ 750/1055T will be usable 2 years from now. You know what I mean? We have seen first hand single core A64 owners suffer this fate, and soon we will see all dual-core owners suffer the same fate. .

I can't even count how many times I have seen people who initially bought E6600/E6850 upgrade to Q9550s to ride this generation out with new GPU cards. On the AMD side, at least you can swap a new CPU since you can get a X4 940 for $100, for example. However, with price parity between a decent dual core and Quad-Core being about $50-70 now, it is too much of a gamble to get a dual-core now when already a lot of games benefit from quads (Starcraft 2, DA:O, Supreme Commander 2, World in Conflict, Civ5, GTAiv, Resident Evil 5, Mass Effect 2). Just my 2 cents on the matter.

 

[cusideabelincoln]

I just don't want to see someone looking to build a system to last 2-3 years go out and buy a Core i3-560 3.33ghz ($150) + GTX460 1GB ($200) over a Core i5 750/1055T ($200) + GTX460 768mb ($150) because of that article. This is exactly the type of advice I fear because it will result in the person upgrading both the GPU and the CPU 2 years from now.

Of course, that would be silly especially considering the performance delta between the two GTX 460s is small.

Also the Core i3 does have hyperthreading, which may have an impact on performance.

We do need some more thorough investigating. I propose someone test a Core i3 at 3 GHz with HT disabled and enabled against a Core i5 quad at 3 GHz with two cores and Turbo disabled and all cores functioning with Turbo disabled. We would have four data points to look at.

Alternatively AMD processors would provide a nice article, too. Test the Phenom 955 against the 555 in a variety of games.

 

[RussianSensation]

Here is BitTech.net using Core i7 980X with 1-6 core testing paired with HD5870/GTX470.

While they arrive at a similar conclusion, they still think the era of dual cores is about to come to an end:

"For those of you with a dual-core CPU, in most games it offers "enough" performance (at least in terms of core count), although it's clear that won't last much longer. While some developers are sticking with engines that aren't multi-threaded, if there's one thing clear from our testing it is that games are starting to make better use of more cores. At the moment, three cores appears to be what games are happiest using. Four CPU cores appears to be plenty, and it's upgrade and multi-task proof. If you do leave your torrent client, MSN on or music playing in the background, for example, then the game will still have enough spare resources not to chug."

 

[crisium]

Huh? You can get a Phenom II X4 955 for ~$140-150 and oc it, and have enough money left over for a GTX460-768MB at ~$140-160 (depending on how you feel about rebates).

Exactly! There's many options! And I'd wager that the Athlon II X3 system with the superior GTX 460 1GB will sometimes be faster than the PhII X4 with the 768MB. Other times the PhII system will be clearly better. That's why I'd like a benchmark evaluating different combination. Your "Huh" implies that it's obvious, but it's not always. How low can you go on the CPU in order to get a better GPU before you start hurting your performance? It depends on a lot of games and we don't have the benchmarks comparing different setups like this.

 

[Patrick Wolf]

It can not transition different perspectives.

Well as Toyota suggested, that wouldn't be a 2 vs 4 core issue. Try disabling 2 cores then running your non-8xAA setttings and see if the problem presents itself.

"For those of you with a dual-core CPU, in most games it offers "enough" performance (at least in terms of core count), although it's clear that won't last much longer. While some developers are sticking with engines that aren't multi-threaded, if there's one thing clear from our testing it is that games are starting to make better use of more cores. At the moment, three cores appears to be what games are happiest using. Four CPU cores appears to be plenty, and it's upgrade and multi-task proof. If you do leave your torrent client, MSN on or music playing in the background, for example, then the game will still have enough spare resources not to chug."

As far as games go, seems like a few rare developers actually make use of modern CPU's capabilities and others just port from the X360 or PS3 who's processors are quite different from what we're sporting in our PC's. I have no idea what kinda hardware the next systems will have (maybe some crazy hybrid CPU/GPU combo) but it'll probably be the greatest determining factor for core utilization in future PC games.

Though many times it's just that the game engine only requires so much muscle from the CPU, even if it uses all cores effectively. Take Bioshock 2 for one example. It maxes out 1 core and going from dual to quad doesn't give you much, but core usage for both is nicely spread out. Then look at AVP. CPU usage is constantly low, even 1 core was ok. Maybe the deveioper's could've made better use of the CPU so it wouldn't be so GPU limited, then again I'm not a programmer so maybe not.

 

[AtenRa]

The following is from the Intel Core i3 540 review I made for a Greek technology site.

A dual core i3 540 with HT at default, 3,7GHz and 4,3GHz vs a quad core Phenom II 955 default and at 3.85GHz.


Intel
CPU: Intel Core i3 540
Motherboard: Asus P7P55D-E (P55)
Memory: 2x KINGSTON KVR1333D3N9/2G DDR3-1333MHz (1333MHz 7-7-7-24)
VGA: ASUS HD5850 (899MHz Core, 1100MHz Memory)
PSU: Enermax Revolution 85+ 850W
HDD : Seagate 500GB 7200rpm SATA-II
Windows 7 Pro EN 64bit
VGA Drivers: Catalyst 10.3
CPU Cooler: Noctua NH-U12P

AMD
CPU: Phenom II x4 955 Black Edition
Motherboard: Asus Crosshair IV Formula
Memory: 2x KINGSTON KVR1333D3N9/2G DDR3-1333MHz (1600MHz 9-9-9-24)
VGA: ASUS HD5850 (899MHz Core, 1100MHz Memory)
PSU: Enermax Revolution 85+ 850W
HDD : Seagate 500GB 7200rpm SATA-II
Windows 7 Pro EN 64bit
VGA Drivers: Catalyst 10.3
CPU Cooler: Noctua NH-U12P

I will only show you the 1920x1080 tables, you can see the 1280 and 1650 in the review.

Even at high resolution of 1920 (no filters) with a HD5850 at 899MHz, most of the games are CPU Bottlenecked

edit reason: Broken link fixed

 

[RussianSensation]

As far as games go, seems like a few rare developers actually make use of modern CPU's capabilities and others just port from the X360 or PS3 who's processors are quite different from what we're sporting in our PC's. I have no idea what kinda hardware the next systems will have (maybe some crazy hybrid CPU/GPU combo) but it'll probably be the greatest determining factor for core utilization in future PC games.

I agree with you completely. At the same time, if I was a developer I probably wouldn't bother diverting my efforts towards a PC game engines either given the limited employee resources and budgets.

Here are pre-orders for Medal of Honor

Xbox360 = 394,803
PS3 = 314,728
PC = 59,049 (8&#37 :$

Here are pre-orders for Call of Duty: Black Ops
Xbox 360 = 969,907
PS3 = 524,774
PC = ?? (Castlevania, 30th game on pre-order list had 40,000 copies) So has to be < 2.7%

No wonder we didn't get a single killer-ap since Crysis in 2007.

Even at high resolution of 1920 (no filters) with a HD5850 at 899MHz, most of the games are CPU Bottlenecked

Your Crysis and WiC results are not realistic because no one plays those games at a steady 60 fps+ with no filters on a $300 graphics card. A more realistic gaming scenario is applying 8AA or 16X CSAA. Steady 30-35 fps + High AA on a PC gaming rig is what gives you the advantage of aiming better in online FPS gaming matches because it is easier to spot enemy units among vast fields of grass/foilage.

8-16AA filters also make it easier to identify 100 of your own units from the enemy units in a strategy game when you have fully zoomed in. The much lower min. frames with the stock i3 540 are likely the result of other factors outside of the CPU such as the game engine, the HDD thrashing, benchmarking run, etc. Plus, since the min. frame only occurred once during mid-battle, rather than as a sequence of continous dips, it hardly had an impact on playability.

 

[blastingcap]

No wonder we didn't get a single killer-ap since Crysis in 2007.

Yup, and companies like to blame piracy. To some extent this is true, but it depends on how you calculate numbers. Each pirated copy does not necessarily mean a lost sale, since many piraters would have never bought the game at all, at any price.

That said, PCs have some exclusives since 2007 that got good reviews and are arguably at least a good as Crysis, including various MMORPGs, all of the RTS games (e.g., Supreme Commander/DoW/StarCraft 2), STALKER CoP, all of the 4X games (e.g., Civ V, all of the Total War games, Sins of a Solar Empire), etc.

And I like how PC gaming by its nature screens out people who are too stupid to understand how PC hardware and software (including drivers) work. Translation: fewer idiot teammates to deal with.

I have also mellowed out about console ports, deciding to go Eyefinity to put spare GPU horsepower to good use. In that sense I don't mind if graphics stagnate a bit thanks to consoles, since Eyefinity really hammers existing GPUs.