CPU for mining rig
Professional mining motherboards often use Intel solutions. Are AMD processors worse at their job?
We're not going to stir up a holy war about the Blue and Red standoff but look at the facts.
We had already said that plugging in and powering up the GPU is not enough for a motherboard to see a graphics card. There should be enough PCI-E lanes to detect a graphics card.
Intel and AMD deal with this issue from different points of view.
Intel decides that only the processor is responsible for the amount of PCI-E graphics lanes.
While AMD processors share PCI-E lanes with the motherboard.
Consider how many PCI-E lanes you need for your mining rig.
The more PCI-E lanes — the better!
Does CPU power necessary?
Cores, threads, frequency, all of that?
CPU power is not essential unless you will mine on a CPU; if you only need it to run your rig and forget about it.
If the CPU is not busy mining, it runs the OS and operates the background processes. So even an old Intel Core Duo E8400 will be enough.
If you are going to mine on a processor - choose the latest and most powerful processor models.
Here is a small list of the most popular and best processors for mining at the beginning of 2022. (Hashrate for RandomX Monero is approximate)
AMD processors:
- AMD Ryzen Threadripper 3970X ~ 24000 H/s RandomX
- AMD Ryzen 9 3950X ~ 12500 H/s RandomX
- AMD Ryzen 7 5800X ~ 6600 H/s RandomX
- And also AMD Ryzen 5-9 Zen 2-3 and better.
Intel processors:
- Intel Core i9-12900K ~ 7700 H/s RandomX
- Intel Xeon E5-2699V3 ~ 2700 H/s RandomX
- Intel Core i7-7700K ~ 2400 H/s RandomX
- And Intel Core i5 - i9 Kaby-Coffee Lake and better
💙Intel
The cheaper — the better!
There is no sense in overpaying for an extra ~200 megahertz or two additional virtual threads that will give no use to you.
The cheap Intel Pentium G4400 LGA 1151 has 16 PCI-E lanes, low power consumption, an integrated graphics card, and two cores to run the operating system, the main programs, and Kryptex. Cheap, good and enough for your rig — up to 12 graphics cards!
Why 12? Since there are 16 PCI-E lanes, there should be 16? — And yes, and No.
The integrated graphics core also takes PCI-E lanes.
The integrated graphics core can take from 4 to 8 PCI-E lanes depending on its type.
The integrated graphics card MAY be disabled in the BIOS, but in this case, you will lose the possibility to display the image from the motherboard, and the mining video cards will have to take more load.
More PCI-E lanes are available from Intel only with the 11th generation processors, which are more expensive. In addition, you have to pick up a new motherboard for them.
Most likely, the new motherboard will not have as many PCI-E slots. You will have to make do with fewer video card slots or use splitters.
You could resort to Intel Xeon server solutions which have more PCI-E lanes. But unfortunately, server motherboards are more expensive and harder to find.
You can look into solutions from Chinese friends like Huananzhi X99-T8.
❤AMD
AMD isn't so clear-cut either.
The old AMD AM2/AM3 processors are significantly inferior in process technology. PCI-E lane distribution logics does not always work correctly. They are hot, consume much power, and have fewer PCI-E lanes (about 6).
If you decide to build a rig using the old AMD AM2/AM3 platform, consider the pros and cons.
The situation has changed with the release of the AM4 platform, but not without nuances.
Yes, there are almost no professional mining motherboards for them, but it is easy to find new motherboards with 6 PCI-E slots.
AMD AM4 processors and motherboards, with more PCI-E slots, are cheaper than their Intel counterparts. Also, AMD has a "complicated" naming and model range.
For example, Athlon 200GE is older and weaker than Athlon 3000G, but it has twice PCI-E lanes!
Athlon 200GE — 12 PCI-E lanes vs Athlon 3000G — 6 PCI-E lanes
Hybrid APU (SoC) A8-A12 processors also lose compared to the youngest Athlon 200GE processor both by power and PCI-E lanes.
The Athlon 200GE has 12 PCI-E lanes versus the older A12-9800 with 8 PCI-E lanes.
When choosing between the Athlon 200GE and Athlon 220GE / Athlon 300GE, we recommend selecting models from 220GE to 300GE.
These models will make your rig run more stable.
Both AMD Athlon and AMD A8-A12 models have a graphics core that will take up PCI-E lanes — we recommend to be disabled it. The practice has shown that Athlon 200GE - Athlon 300GE can work stably with a farm of up to 6 video cards. They are budget, office processors, after all.
For stable mining, you must disable the Vega integrated graphics core
If you're building a large mining rig on with AMD platform, start with AMD Ryzen processors.
The AMD Ryzen 3 1200 processor will easily take six or more video cards and will not cause graphics problems (it has no integrated graphics card). The Ryzen 3 1200 has 20 lanes of PCI-E versus the oldest Athlon with its 12 lanes.
Astonishingly, the Ryzen 3 1200 even costs less than the Athlon 300GE
The AMD Ryzen processors mine Monero RandomX much better than their Intel counterparts in the same price range.
A Ryzen 3 can hardly boast a high hash rate, but a Ryzen 5 1600 with dual memory channel mode and high RAM frequency would give you ~4500 H/s RandomX.
What affects the hash rate of the processors — read our article.
Compatibility
Always check if your CPU and motherboard are compatible!
For example, Intel sockets:
LGA 1151 and LGA 1151-v2 are completely different sockets!
An LGA 1151 processor will fit into the LGA 1151-v2 socket, but it will not work, and even a BIOS update will not help.
Check their compatibility before buying the processor and motherboard.
Some CPUs and motherboards are compatible “from the box,” as evidenced by the inscription on the product itself.
Sometimes you may need to install a newer version of the motherboard BIOS to support the processor. Or it can happen that the processor and motherboard are not compatible at all, even though they have the same connector type.
What's the best way to be sure?
Motherboard manufacturers regularly update their compatibility databases, so check before you buy.
- Manufacturer's compatibility ASUS
- Manufacturer's compatibility MSI (the most inconvenient option— you will have to search for each specific motherboard model)
- Manufacturer's compatibility ASRock
- Manufacturer's compatibility Gigabyte
- Manufacturer's compatibility Biostar
Processor Cooling
No matter which CPU you choose, there are two options: Box and Tray (OEM).
Box — CPU cooler is included with the processor.
Tray (OEM) — CPU only, without cooler.
The Box package is more expensive and has a longer warranty. The Tray (OEM) package is cheaper and has a less warranty.
The basic cooler is good enough, it saves you money (you don't have to buy a cooler separately), but it's not suitable for mining. The OEM coolers are quiet and low-powered. Their job is to cool the processor under average load.
If the processor is going to mine, find a good cooler for the processor.
If your processor WON'T mine, the Box option is the best choice!
Overheating can cause the processor throttling — dropping clock speed to cool itself, which means you earn less.
Processor power
The more powerful the processor, the more its TDP — more power consumption, heat, and higher hash rate... But not always.
Old processors like AMD FX-8350 have a whopping 125 Watt TDP and are unsuitable for mining.
While AMD Ryzen 1600 has only 65 Watts TDP and can mine ~4500 H/s RandomX
Based on your CPU's TDP, calculate your power consumption so that your power supply has enough power for all your video cards.
The processor is powered by the ATX lane, represented as a square connector with four pins. The more power the processor consumes, the more connectors it needs to power it.
CPU power can be represented as a single four-pin connector, a dual 4+4 pin connector, or an entire eight-pin connector.
The more powerful the power supply is, the more processor's pins it will have.
Not to be confused with graphics card connections, these are different connections!
CPU power connector
Let's summarize.
- Any CPU will be OK for your Rig as long as it has enough PCI-E lanes to support your video cards.
- Carefully match the CPU to the motherboard. Ensure that the socket match and that the motherboard chipset supports your CPU. Make sure that your motherboard BIOS is ready to support your CPU (sometimes, you may need to update your BIOS to support it).
- If the processor won't be mining, its power is unimportant.
- Do you want a mining motherboard? Choose Intel!
- Want a cheap and modern motherboard that can connect up to 6 video cards? Choose AMD!
- The integrated graphics card eats up precious PCI-E lanes - disable it if your rig runs unstable or if the graphics card is not detected!
- Want to mine Monero on a CPU?
- The best processor for mining is AMD Ryzen Threadripper.
- Choose AMD Ryzen processors from Ryzen 5 1600 and above.
- Choose Intel processors from 7th generation Core i7 and up.
- Do you want to save money?
- Choose a BOX CPU if you don't have a cooler.
- Choose the Tray CPU package if you have a cooler and don't want any extra junk, and want to save money.
Any more questions about your choice? We're waiting for you on our Discord or Telegram!
