Choosing a processor is becoming an increasingly difficult experience given the speeds, number of cores and threads, cache sizes, socket types and price points to which we are exposed. The megahertz alone can no longer be a deciding factor as they were in the past. Today's processors are truly multidimensional collections of features, but it is difficult to understand any of these dimensions in isolation. What we would like then is to reduce the number of dimensions to observe more clearly patterns that may arise.
Here we will take a look at the specifications of some Intel processors (desktop and server). You can easily find them on the company's website, when you are in processor comparison mode. We will consider features like lithography, price range (from-to), number of cores, number of threads, base frequency, max turbo frequency, cache size, TDP, maximum memory size supported, memory type (e.g. DDR4-2166), maximum memory channels, PCI Express revision, maximum PCI Express lanes. Here that data is presented in a compact comma-separated format.
I9-7900X,14,989,999,10,20,3300,4300,13.75,140,128,2666,4,3.0,44 I7-7820X,14,589,599,8,16,3600,4300,11,140,128,2666,4,3.0,28 I7-7800X,14,383,389,6,12,3500,4000,8.25,140,128,2400,4,3.0,28 I7-7740X,14,339,350,4,8,4300,4500,8,112,64,2666,2,3.0,16 I5-7640X,14,242,243,4,4,4000,4200,6,112,64,2666,2,3.0,16 IT-6950X,14,1723,1743,10,20,3000,3500,25,140,128,2400,4,3.0,40 IT-6900K,14,1089,1109,8,16,3200,3700,20,140,128,2400,4,3.0,40 I7-6850K,14,617,628,6,12,3600,3800,15,140,128,2400,4,3.0,40 I7-6800K,14,434,441,6,12,3400,3600,15,140,128,2400,4,3.0,28 I7-5960X,22,999,1059,8,16,3000,3500,20,140,64,2133,4,3.0,40 I7-5930K,22,583,594,6,12,3500,3700,15,140,64,2133,4,3.0,40 I7-5820K,22,389,396,6,12,3300,3600,15,140,64,2133,4,3.0,28 I7-4860X,22,1059,1059,6,12,3600,4000,15,130,64,1866,4,3.0,40 I7-4940MX,22,-1,-1,4,8,3100,4000,8,57,32,1600,2,3.0,16 I7-4930K,22,594,594,6,12,3400,3900,12,130,64,1866,4,3.0,40 I7-4930MX,22,-1,-1,4,8,3000,3900,8,57,32,1600,2,3.0,16 I7-4820K,22,332,332,4,8,3700,3900,10,130,64,1866,4,3.0,40 I7-3970X,32,1059,1059,6,12,3500,4000,15,150,64,1600,4,2.0,40 I7-3960X,32,1059,1059,6,12,3300,3900,15,130,64,1600,4,2.0,40 I7-3940XM,22,1096,1096,4,8,3000,3900,8,55,32,1600,2,3.0,16 I7-3930K,32,594,594,6,12,3200,3800,12,130,64,1600,4,2.0,40 I7-3920XM,22,1096,1096,4,8,2900,3800,8,55,32,1600,2,3.0,16 I7-3820,32,305,305,4,8,3600,3800,10,130,64,1600,4,2.0,40
Since the number of processors is relatively small, we can easily see how they are positioned across a spectrum. Notice how the two processors I7-4930MX and I7-4940MX appear in the bottom left of the graphic. They have unknown price points (given as -1 in the data) and were included only for completeness. Now we notice that IT-6950X appears on the very right of the plot. If we return to the data to see why it has such a score, we will observe that this is the most expensive processor with the highest number of cores and threads (together with the IT-6900K) and the biggest cache size. Now we can shift our attention to the other axis. Why is I7-7740X there? It could be again for various reasons. It is relatively inexpensive, but has very high clock speeds (4300-4500Mhz) with acceptable 8MB cache and TDP given only as 112W, compared to other models which have full 140W. Why is I5-7640X slightly lower on the y-axis? It is cheaper, but in many areas also less performant. It also has only 6MB cache. On the right of it we notice two other models with caches of 11MB and 13.75MB accordingly. We see that with increasing cache sizes we are quickly moving to the right of the plot—where the most expensive processor was. But how is it then possible that the model I7-3820, which is one of the cheapest comes with 10MB cache (lower left)? This might suggest not only a difference in the size, but also in the speed of the cache, the lithography or else. On the bottom right are 3920XM and 3940XM—expensive processors, supporting only 32GB memory and memory speeds only up to 1600Mhz, but while being very energy-efficient (55W vs 130W).
Xeon Platinum 8180M,14,13011,13011,28,56,2500,3800,38.5,205,1500,2666,6,3.0,48 Xeon Platinum 8180,14,10009,10009,28,56,2500,3800,38.5,205,768,2666,6,3.0,48 Xeon Platinum 8176M,14,11722,11722,28,56,2100,3800,38.5,165,1500,2666,6,3.0,48 Xeon Platinum 8176F,14,-1,-1,28,56,2100,3800,38.5,173,768,2666,6,3.0,48 Xeon Platinum 8176,14,8719,8719,28,56,2100,3800,38.5,165,768,2666,6,3.0,40 Xeon Platinum 8170M,14,10409,10409,26,52,2100,3700,35.75,165,1500,2666,6,3.0,48 Xeon Platinum 8170,14,7405,7411,26,52,2100,3700,35.75,165,768,2666,6,3.0,48 Xeon Platinum 8168,14,5890,5890,24,48,2700,3700,33,205,768,2666,6,3.0,48 Xeon Platinum 8164,14,6114,6120,26,52,2000,3700,35.75,150,768,2666,6,3.0,48 Xeon Platinum 8160T,14,4936,4936,24,48,2100,3700,33,150,768,2666,6,3.0,48 Xeon Platinum 8160M,14,7704,7704,24,48,2100,3700,33,150,1500,2666,6,3.0,48 Xeon Platinum 8160F,14,4856,4856,24,48,2100,3700,33,160,768,2666,6,3.0,48 Xeon Platinum 8160,14,4702,4708,24,48,2100,3700,33,150,768,2666,6,3.0,48 Xeon Platinum 8158,14,7007,7007,12,24,3000,3700,24.75,150,768,2666,6,3.0,48 Xeon Platinum 8156,14,7007,7007,4,8,3600,3700,16.5,105,768,2666,6,3.0,48 Xeon Platinum 8153,14,3115,3115,16,32,2000,2800,22,125,768,2666,6,3.0,48 Xeon Gold 6154,14,3543,3543,18,36,3000,3700,24.75,200,768,2666,6,3.0,48 Xeon Gold 6152,14,3655,3661,22,44,2100,3700,30.25,140,768,2666,6,3.0,48 Xeon Gold 6150,14,3358,3358,18,36,2700,3700,24.75,165,768,2666,6,3.0,48 Xeon Gold 6148F,14,3227,3227,20,40,2400,3700,27.5,160,768,2666,6,3.0,48 Xeon Gold 6148,14,3072,3078,20,40,2400,3700,27.5,150,768,2666,6,3.0,48 Xeon Gold 6146,14,3286,3286,12,24,3200,4200,24.75,165,768,2666,6,3.0,48 Xeon Gold 6144,14,2925,2925,8,16,3500,4200,24.75,150,768,2666,6,3.0,48 Xeon Gold 6142M,14,5949,5949,16,32,2600,3700,22,150,1500,2666,6,3.0,48 Xeon Gold 6142F,14,3101,3101,16,32,2600,3700,22,160,768,2666,6,3.0,48 Xeon Gold 6142,14,2946,2952,16,32,2600,3700,22,150,768,2666,6,3.0,48 Xeon Gold 6140M,14,5448,5448,18,36,2300,3700,24.75,140,1500,2666,6,3.0,48 Xeon Gold 6140,14,2445,2451,18,36,2300,3700,24.75,140,768,2666,6,3.0,48 Xeon Gold 6138T,14,2742,2742,20,40,2000,3700,27.5,125,768,2666,6,3.0,48 Xeon Gold 6138F,14,2767,2767,20,40,2000,3700,27.5,135,768,2666,6,3.0,48 Xeon Gold 6138,14,2612,2618,20,40,2000,3700,27.5,125,768,2666,6,3.0,48 Xeon Gold 6136,14,2460,2460,12,24,3000,3700,24.75,150,768,2666,6,3.0,48 Xeon Gold 6134M,14,5217,5217,8,16,3200,3700,24.75,130,1500,2666,6,3.0,48 Xeon Gold 6134,14,2214,2220,8,16,3200,3700,24.75,130,768,2666,6,3.0,48 Xeon Gold 6132,14,2111,2111,14,28,2600,3700,19.35,140,768,2666,6,3.0,48 Xeon Gold 6130T,14,1988,1988,16,32,2100,3700,22,125,768,2666,6,3.0,48 Xeon Gold 6130F,14,2049,2049,16,32,2100,3700,22,135,768,2666,6,3.0,48 Xeon Gold 6130,14,1894,1900,16,32,2100,3700,22,125,768,2666,6,3.0,48 Xeon Gold 6128,14,1691,1697,6,12,3400,3700,19.25,115,768,2666,6,3.0,48 Xeon Gold 6126T,14,1865,1865,12,24,2600,3700,19.25,125,768,2666,6,3.0,48 Xeon Gold 6126F,14,1931,1931,12,24,2600,3700,19.25,135,768,2666,6,3.0,48 Xeon Gold 6126,14,1776,1776,12,24,2600,3700,19.25,125,768,2666,6,3.0,48 Xeon Gold 5122,14,1221,1227,4,8,3600,3700,16.5,105,768,2666,6,3.0,48 Xeon Gold 5120T,14,1727,1727,14,28,2200,3200,19.25,105,768,2400,6,3.0,48 Xeon Gold 5120,14,1555,1561,14,28,2200,3200,19.25,105,768,2400,6,3.0,48 Xeon Gold 5119T,14,-1,-1,14,28,1900,3200,19.25,85,768,2400,6,3.0,48 Xeon Gold 5118,14,1273,1273,12,24,2300,3200,16.5,105,768,2400,6,3.0,48 Xeon Gold 5115,14,1221,1221,10,20,2400,3200,13.75,85,768,2400,6,3.0,48 Xeon Silver 4116T,14,-1,-1,12,24,2100,3000,16.5,85,768,2400,6,3.0,48 Xeon Silver 4116,14,1002,1012,12,24,2100,3000,16.5,85,768,2400,6,3.0,48 Xeon Silver 4114T,14,-1,-1,10,20,2200,3000,14,85,768,2400,6,3.0,48 Xeon Silver 4114,14,694,704,10,20,2200,3000,13.75,85,768,2400,6,3.0,48 Xeon Silver 4112,14,473,483,4,8,2600,3000,8.25,85,768,2400,6,3.0,48 Xeon Silver 4110,14,501,511,8,16,2100,3000,11,85,768,2400,6,3.0,48 Xeon Silver 4109T,14,501,501,8,16,2000,3000,11,70,768,2400,6,3.0,48 Xeon Silver 4108,14,417,427,8,16,1800,3000,11,85,768,2400,6,3.0,48
There are a lot more Xeon models for servers, so we cannot possibly discuss them all here. (Click on the graphic to see it enlarged). On the left of the plot are four points that have the same x-value—these are models without a given recommended price (we can't say much about them). Some labels overlap, but this means that there are many processors with similar characteristics. The models that appear on their own are much more interesting here.
Platinum 8180M is given as the most expensive, but also providing a lot of value, so it is on the right. Platinum 8156 (diagonal-out) is interesting as being very expensive, but with smaller cache (compared to other models of the same series) and high energy-efficiency (105W vs. 150-165W). Servers are often expected to work nonstop, so this might be important. Xeon Gold 6134M is even cheaper, having a slightly bigger cache and up to 1.5TB memory support. Platinum 8153 (bottom on the chart) is relatively cheap and at the same time suitable for very high multitasking environments, since it has 16 cores (although at a lower clock speed). As you can see from the graphic it is both far from the other Platinums and also well-separated from most Gold models.
Xeon Gold 5122 has only four very-high frequency cores compared to other Gold processors with 12-14 cores, so in server settings it will likely be only interesting for short, one-time tasks that must be executed fast.
Approximately at the center of the plot is Xeon Gold 6150, which means that it is (likely) providing a good price-performance ratio. Similar models can be slightly cheaper and have two cores (or four threads) more than it, but their base frequency is 300Mhz lower, which for 18 cores will matter perhaps slightly more than the loss of two cores of 2400Mhz. Gold 6140 has the same number of cores as Gold 6150 and is ≈30% cheaper, the only difference being that its per-core frequency is 2300Mhz instead of 2700Mhz, but it also has the large 24.75MB cache.
According to the graphic, Silver 4108 must be a good entry model, since it is cheap and comes with 8 cores and 11MB cache. Its maximal turbo frequency is the same as all other Silver models, yet its base frequency is only 1800Mhz, so it could be even more efficient if left idle. If you want to have 50% threads more and 50% larger cache at 3x the price, you might want to consider Gold 5118, but that model will also use 20W more. Silver 4112 has half the cores and smaller cache than 4108, but it has 800Mhz higher per-core frequency.
Please, notice that these observations are based on the specifications only, not on performance comparisons with real-world applications.