Using an i3 CPU with the Dell 7020/9020 OptiMac
In the main guide I had previously dissuaded readers from using a
Core i3 CPU in favor of an i5. Since then I've tested out a few i3's in both the MT and the SFF model. I've concluded that it does make sense to use an i3 which has
HD4600, but not one with HD4400. If you dual boot with Windows 10, definitely go for the quad core i5 or i7 Intel Haswell CPU. Dual core i3 CPUs do not perform well enough for any serious gaming. The i3s do have faster single core performance but fall far behind in multi-core performance which modern games require. On the other hand Mojave/Catalina/Big Sur are not the resource hogs that Windows 10 is. A dual core Haswell i3 clocked at 3.5 or 3.6 GHz performs quite snappily with at least 8GB of ram and an SSD boot drive.
HD4400 Graphics are Rather Disappointing
I've tried using the i3-4150 (HD4400) while spoofing HD4600. The results were not great. It works somewhat but not to the degree I'd ever be happy with on a daily basis. I've also tested out an i3-4330 which has HD4600 igpu and it works quite well. Stays cool and hardly uses any electricity during general use. You can also buy these used for about 15-20 dollars less than most of the i5 Haswell CPUs such as the i5-4570 and i5-4670.
If you do want to save money and energy, here are the Haswell i3 models that you can buy and install in your Dell OptiMac. They all have HD4600.
Avoid the HD4400 versions such as the
i3-4150 and
i3-4160. The prices of the i3-4150/60 CPUs are just a few dollars lower than the suggested HD4600 models so it makes no sense to buy one.
Suggested i3 CPUs with HD4600 Graphics
Here's some charts of the CPU temps while running the fans in an SFF with the i3-4150 CPU at the lowest and highest speeds. They are way too noisy at the highest 4500 RPM speeds but are very tolerable at the lowest settings. Maxing out the fans doesn't lower the idle CPU temps more than around 2 degrees C. I can verify that Dell did an excellent job of thermal management in this professional Optiplex line. Over heating is never a problem.