The Most Practical Low-End Through High-End CPU's for a Standard PC
Intel's Coffee Lake Refresh platform delivers unprecidented value. From this platform, we have chosen three CPU's to consider in creating a highest-value practical PC.
There are three processing bottlenecks in a PC: raw core speed, single queue 4K random read, and virtual paging overflow.
It is very common for people to think that their CPU is the bottleneck when it is more likely the random read bottleneck. And most advice still focuses on fixing the virtual paging overflow bottleneck, which will in turn make the random read bottleneck worse, because their solutions are in a tug-a-war. This often confuses both experts and system optimizers, leading to the wrong configuration, which then makes a PC slow down prematurely.
How do you tell if its a CPU bottleneck? Software that is doing a lot with data in RAM, such as program data, and not with data on disk. An excellent candidate is CAD work. If your CAD drawings are quite detailed then you should look for a fast CPU.
CPU performance is for some people a very big factor. This is likely the bottleneck in CAD engineering, some types of games, servers generating pages dynamically, and large scale data analytics. So, what should we look for in a CPU to speed these up?
Its the balance between the number of threads and the speed of threads that you have to determine in choosing a CPU. The vast majority of software on the planet is not fully optimized for thread use, and as a result chokes up on thread or core speed rather than thread or core count. For this reason it is usually more important that your CPU have a good sustained raw core speed. All the Coffee Lake Refresh CPU's are great in this department. However, if your software makes good use of threading, or you are running a lot of programs simultaneously, then more cores and/or threads is also important.
The Coffee Lake Refresh i3 actually includes 4 cores, which is quite an improvement from the previous platforms. With 4 cores it can perform moderate threading, which makes a very big difference a lot of the time. However, if your software emphasis is threading then more would be better. In this case you should choose either the i5, which is very good if on a budget, or the i9, which is the very best from Intel's Coffee Lake Refresh platform.
AMD currently has Intel topped on the number of threads, but Intel has faster threads. Faster threads are almost always the more important of the two. However, they are both a factor. So, as your CPU speed requirements go up, you should try to get more of both.
The Gigahertz rating of the CPU directly translates into CPU speed. And the faster the CPU the faster the RAM you'll need to avoid a choke-point there. Generally, all these factors improve as you climb through the generations of platforms. Coffee Lake Refresh is a gen9 platform.
Today it is no longer just about the CPU. Instead we talk about the CPU platform, which includes all sorts of special technologies, some of which are quite important. Its for this reason that going back to an older platform is a bad idea. You'll lose out on so much. In the case of Coffee Lake Refresh, you get a new SSD interface called an "NVMe M.2" that delivers drive speeds that are 20x faster than a hard drive, and DDR4 capability, which is a new type of RAM that is way faster and more reliable than anything used previously. These capabilities combine to allow the operating system to produce a vastly better disk cache. (Remember how this is part of the solution to the 1 queue random 4K read bottleneck?) So, in choosing the best CPU to fix the CPU bottleneck, you are also helping to fix the other bottlenecks.
These are the winning CPU's...
The world's most practical low-end CPU: Intel Coffee Lake Refresh i3-9100. (NOTE: this i3 includes turbo and Quick Sync)
The world's most practical medium grade CPU: Intel Coffee Lake Refresh i5-9600.
The world's most practical high-end CPU: Intel Coffee Lake Refresh i9-9900.