I’ve always been led to believe that when it comes to a system’s performance, memory and the video card are going to be much more important than the clock speed. But I want to understand just how important it is - the Wiki on clock rate doesn’t tell me much other than “higher clock speed is better”.
For some specific examples, I’m comparing my current computer, which is about 4-5 years old, to some models I am considering purchasing so I can play the latest games, which are starting to get awfully choppy on this one.
My current PC has a 2.8 GHz Pentium D with 1 GB RAM and an NVIDIA GeForce 6800. One example of a PC I’m looking at is this one, which has 6 gigs of memory and a GeForce GTS 150 which I know will blow my current PC out of the water - but I also notice it has a 2.66 GHz processor, a number actually lower than the 2.8 GHz I currently have. Of course, it’s a “Intel® Core™ i7-920 Processor (2.66GHz Quad-Core with Intelreg; Hyper-Threading & Turbo Speed Technology)”. I have no clue what the hell any of that means, but I assume it’s probably better in other ways besides the clock speed.
So what does clock speed really mean in gaming performance terms and how important is it really? What are other important features of a processor? (Quad-core? Turbo Speed? Sounds fancy enough…)
Read sites that deal with this because we can’t cover it all here. Overclocker sites will go into great detail of what the stuff does. The new AMD and Intel chips are farther apart in how they work than ever.
I will cover one thing. The operating speed is import to be high for most processor intensive programs because they don’t use multiple cores to run. A 3.0GHz 2 core maybe better than a 2.4 GHz 4 core for what you want. A 3.0 GHz 4 core would be better than a 3.0 GHz 2 core for sure. Some programs can use multicore processing but don’t count on it. The one thing multicore processors will help on is running the OS and other programs on the other cores freeing one core to process your program at the full speed of one core.
When comparing similar processors, (ie from the same family and manufacturer), clock speed can be used as a differentiator - faster is better. It is much harder to to compare processors from different manufacturers (like AMD vs Intel) based on clock speed, due to the different ways the processors work internally.
For most workloads, more cores will give some benefit, but the gains are not generally linear - for most tasks a quad-core CPU will not be twice as fast as a dual-core CPU at the same clock speed, and for some tasks may not be faster at all. Some tasks (as more applications are multi-threaded/multi-core aware) will gain almost all the benefit from multithreading.
Hyperthreading is an Intel trick to utilise cpu (core) resources that are not always working. Since the processor works as a linear pipeline (so bits at the beginning are idle while the end is finishing), Intel added functionality to use the idle parts of the pipeline, sort of running twice as much processing through the cpu core. When Hyperthreading is enabled on an i7 quad-core, the OS will see 8 virtual cores. Of course, the true throughput is somewhat more than 4 cores, but significantly less than 8 cores. The true value is dependent on the instructions being executed in the hyperthreads - for some instructions, there may be no benefit from hyperthreading (due to the way the cpu pipeline is used).
So more cores are better, faster speeds are better, but look at real-world benchmarks paying attention to your specific use-cases to determine the best processor for your requirements.
It is a complex question and there are more variables than anyone not in the business would care to consider.
So to break it down to the simple… You’ve stated your goal is to play the latest games. Most of the games worth playing are multi-core aware and will wring every last drop of performance they can out of them. So the more cores the better, don’t even consider a system that’s not multi-core. Or better yet, restrict your search to quads and then check some of the benchmark sites to compare performances.
Also, there’s a web tool Can You Run It that has almost all games and their minimum and recommended requirements that you can check to get some target numbers for processors, video cards, and ram. Just pick your game from the dropdown and hit go. The computer you’re using will probably fail, but it will tell you what you would have needed to pass.
Higher clock rate is generally better, but there are other considerations:
Clocks per instruction: a CPU that uses 5 clocks for an instruction will be faster than one which uses 7 for the same instruction.
Pipelines: think of an assembly line. The longer the better, except when the pipeline stalls.
Power: self-explanatory.
But really, you don’t need a new CPU. Yours is plenty fast enough; what you do need is a better graphics card and more memory (I suggest 2-4 GB), and if you’re stuck with an AGP motherboard, you’ll need to get a new PCI Express motherboard, CPU, and memory.
BTW if you are chucking it, I have need of a Pentium D CPU…
I’m involved with processor design, and when doing competitive analysis no one looks much at clock speeds. Instead, a set of performance benchmarks are used, representing different workloads. I know there are lists of benchmark results for various CPUs around, the quick search I did didn’t find them directly, though they should be no more than one or two links away from the cited article.
The major effort in computer design is designing a new pipeline, which represents the microoperations an instruction goes through to get executed. Once that is done, the speed increases by finding the slowest paths in the design and fixing them, and by process improvements. The clock speed is more or less the rate at which an instruction goes through the pipe. However, often the instruction gets stalled in the pipe waiting for data from memory, so that isn’t an absolute measure.
Multicore CPUs make it even harder to judge. They’ve become popular because it is easier to design a processor with four copies of a core than one with one gigantic, complex core. Another reason is that power and heat is tied to clock speed, so if you get the same performance from four slower cores as one or two faster ones you win.
Threading, which has already explained, is one way of making use of these extra cores.
The size of the cache is another issue. You can increase performance without increasing clock speed by including a bigger cache - it is also an efficient way to use up available transistors.
A processor doesn’t have only one clock speed. There are several clock domains, with I/O, for instance, being done in one that runs much slower than the main CPU domain.
So, forget about clock speeds and find benchmark results, and worry about caches, having enough memory, and all the other stuff that really counts.
I’d say tomshardware.com is a good benchmark resource (if occasionally accused of bias by both sides of any major brand name war. =P)
Roughly, the short version about clock speed is this–you can only compare clock speed directly between processors of the same type. For example, judging by the “3dMark Vantage CPU” benchmark, that Core i7 920 will be somewhere around twice to three times the speed on CPU-related tasks as the Pentium D 2.8 you describe. Now, keeping in mind that’s a synthetic benchmark and not a real-world test, that’s still a hefty performance increase.
There’s just no good numbers for “how much work can be done per clock cycle” which is the other half of the CPU power equation.
Also, the other posters are somewhat right–that Pentium D isn’t bad for gaming, what you really need is 4GB of RAM and a reasonably modern video card.
You’ve kind of contradicted yourself here. A longer pipeline does take more clocks. The reason it isn’t a real contradiction that longer pipelines tend to have less logic at each stage, and thus can tolerate a faster CPU clock rate. The important metric is not how long one instruction takes through the pipe, but the rate at which instructions come out of the pipe completed. Plus the accuracy of branch prediction and all that other complicated stuff.
The GTS 150 (basically an underclocked GTS 250, which itself is a rebranding of the 9800GTX, which was a pretty minor update of the 8800GTX), while *certainly *a better videocard than your 6800, isn’t really all that fantastic for the money you’re spending on the rest of the computer. The card by itself is maybe only $100-$110. The i7-920 CPU in the same system you’re looking is more than double that ($280). For a gaming computer, a good rule of thumb is to spend at least the same amount of money on the GPU as the CPU, considering the GPU does a majority of the work.
You might want to consider either scaling back on your CPU (and saving some money), or spending a bit more on you GPU (and getting a GTX 275 or ATI HD4890)
Rigamarole, I used to tell my customers a very handy car analogy which I think works to describe the difference between your old computer and your new one, thusly:
Your old computer’s processor was built in the last-generation, when intel was focused on creating rip-roarin’ high-clocking CPUs. Similar to muscle cars of the late 70s-80s (or something…).
At one point, Intel decided that while they could cram more and more horses into an engine, there would be a point down the road where they’d come to a dead stop, where even squeezing one more horse out of the engine would take an inordinate amount of R&D money. At the same time, AMD had been churning out chips that easily matched Intel chips’ power, at a lower clock speed.
So, they decided to backpedal and focus on efficiency, like AMD. This is where the Core2Solo/Duo/Quad processors come in. They came onto the market with efficiency in mind, so a beefy 3.2 GHz P4 from the last generation paled in comparison to a nimble 2.66 GHz Core2Solo.
Duo and Quad refer to the number of logical cores on the CPU. The more the better.
To help you actually understand it, imagine that there’s a machine with a crank. It’s engineered such that one rotation of the crank takes some data, processes it according to some formula, and outputs the result. Most formulas only take the one crank to get the end result, while as others you have to take the output and feed it back through a few more times. But nothing takes less than one crank to power through.
How many fast the crank usually gets rotated is the clock speed. You can think of it like RPM. Modern, multicore processors, can then be thought of as gears which allow you to get more out the processor without having to spin the crank faster and faster. You can think of a multicore processor as two (or more) machines with cranks and a little dude that splits out the data that needs to be processed between them. For technical reason having double or quadruple the cores doesn’t double and quadruple the output, but certainly the more of them the better.
Now what relevance this has to gaming sort of varies. Not everything goes through the CPU these days. Graphics cards have their own CPUs that games can utilize via DirectX or OpenGL. And the slowest point of modern computers–the thing which hasn’t scaled as well as everything else–is the hard drive, so you can have the fastest CPU and the fastest graphics card ever, but if you have a small RAM and a slow hard drive, it’s going to stumble about trying to load and release all the files it needs from the hard drive.
Really the best way to think of it is that every piece marches in time at its own pace but is also fully necessary. And every component will have it’s average cost and bell curve of price drop off and increase as compared to its level of throughput. If you want an average-capability machine, buy all the average priced components today and a game today will run on it at an average level. Buy the components in the 90th percentile of cost and your game will run impressively.
Where you run into problems is if you try and maximize a few things like your CPU and your graphics card, but then go bargain basement for your other components. You can essentially think of it in the terms that your computer will only run a game according to the weakest link in the chain.
So…keep an eye on the stats as you’re shopping, but just to make sure that something isn’t being sold with an inflated price. Otherwise, ignore the stats and just buy according to whatever price percentile you’re buying at.
What if you have sufficient RAM but a low hard drive- will that impede the speed much?
Secondly, how do you know the speed of the hard drive? I am looking at the specs of my computer and can’t find it anywhere (well maybe I don’t recognise it).
Pretty much all consumer-level hard drives are the same speed these days–typically you’d be looking for seek time (in nanoseconds) or RPM (which will be 7200 (typical), 10000, or 15000)–you only see the latter on particularly high-end machines, the typical brand here is Western Digital Raptor, or more generally you’d see the higher speeds on SAS/SCSI type drives as opposed to SATA drives.
Also, I’m going to disagree with Sage Rat here. The hard drive speed is the least of your worries, because every programmer KNOWS it’s a bottleneck and codes to dump stuff in RAM appropriately.
My general point was that the people who make games fashion it according to what is available. Pointing out that hard drives is slow wasn’t saying to look for a fast hard drive, it was a demonstration of the importance of every part.
The key stat for most hard drives is going to be size. Games expand their size based on what users can feasibly keep installed along a few other games and Windows and other software. Most games these days are a gigabyte or three in size, and that’s just going to get bigger.
Though due to load times and production time to create massive content, possibly software size will start peaking, but once you get a big hard drive, then you can start buying full movies in HD over iTunes and stuff. Just figure that regardless of what you buy, the world isn’t going to let any extra space or speed go to waste.
In reading the many answers, I am somewhat more basic in my knowledge of clock speeds. What I am trying to determine is – if games are runring say 3ghz pentimum 4 processor and 1gb of ram - like OBLIVION does – will a dual core 2.6ghz processor meet their recommend system requirements?
I have an Intel 4 - 3ghz now but looking at buying a new computer but not sure if I can save a few bucks and buy a dual or quad core but at say a 2.2ghz procerssor OR do I still need the 3ghz regardless of how many cores?
And if I inlcuded a better quality video card then could I get by with a lower processor speed?
It probably depends on specifics of the game, but in general, current desktop CPUs like Intel’s dual cores - and all the related infrastructure, like RAM speed - are much faster (even if you only count one core - and older games probably will only effectively use one core) than the older pentium 4 systems. I would guess that a 2.2 Ghz dual core would be more than enough.
As some other posters hinted at, if you want to run current “high-end-ish” games, it doesn’t help to put all your money in one basket - though I would consider hard drive speed relatively unimportant - you generally want a reasonably fast CPU with fast RAM to match, and a decent graphics card. Spending, say, $200 instead of $150 on a CPU probably won’t be as useful for gaming as spending $100 instead of $50 on a graphics card.
There’s generally a certain price point of diminishing returns for any given component. For instance, hard drives are generally the best deal (in Gb/dollar) at around $80, and have been for years. Desktop CPUs seem to be around $100 - $140 or so (but CPU prices are much more volatile, and I don’t keep up with them).
Since somebody kicked this thread back up, I might as well mention this here instead of starting a new thread.
I decided instead of spending money on a new computer right now I’m just gonna go ahead and upgrade my RAM and graphics card. I want to buy this card, but am unsure how to tell if it will be compatible with my computer and operating system (XP SP3). I mean, I’m guessing I’ll be able to just pop it in and it will work (after installing drivers of course) but I’ve never done this before so I just want to make sure.
The more important thing is whether you have a PCI Express motherboard. If you’ve got that, you’re golden, as XP support is pretty much a given (and I checked just to make sure.) Though I would consider upgrading to Vista to take advantage of the DirectX 10 support. With the right settings, Vista can run pretty much the same as XP, or better, as long as you’ve got the memory.
