processor

So now you know how to find out which processors are compatible with your system after reading my General CPU Compatibility Guide, but which one is the right one for your usage? Which option will give you the best value and what will work the fastest for you? Which one is going to turn your computer into a space heater and what is going to save you money on your energy bill? There are lots of things to consider when choosing a processor and in many cases, it isn't as simple as buying the most expensive one you can afford.  I will guide you through this consideration process and help you make a smart decision

Budget

Some people will disagree with this, but I think the first thing to consider about your budget is that it is largely irrelevant. Don't come in with the mindset that you have $300 to spend. Instead, evaluate the task you are doing and try to get the processor that will do the best job for you for the least amount of money. What I mean by this is that if you are just doing standard office tasks like web browsing, excel or word then there is very little to gain from having a $300 dollar processor. You would have your needs met all the same for under $100. On the flipside, a $1000 processor may seem absurd to some. That is more than many people's computers cost now. But if you are someone doing hard rendering work or video encoding or some other intensive task and buying a $1000 processor instead of a $300 processor is going to save you 30 minutes a day and you value your working time at $25 an hour, you will earn that value back in less than a quarter of the year. This is why I tell most people who have a number in their head to throw it out the window. Adhering to an arbitrary budget will likely make you spend too much or too little. The important thing is to get your need met in the most efficient way possible.

Usage

In my opinion evaluating your usage is the most important thing to look at when deciding which processor to buy. What I mean by usage is very simply just what you do throughout the day or what you plan to do throughout the day on this computer. Is it a box just for streaming video? Is it a video editing station? Is it a 4k video game rig? Does it need to host piles of virtual machines? Whatever it is doing, consider the software that will be run. Is it something that functions in a good-enough fashion? It either does the job correctly or doesn't. Or is it a speed-benefitting task? Would a faster processor save you time or give you better performance in the task? If, for example, you are playing video games, after a certain point there is no benefit to a faster processor. You have already reached an acceptable frames per second and the game will be enjoyable at the resolution you are using. But if your game is just on the cusp of being playable it may be very worth it to go for the higher clocked processor.

Multithreading

So now you have considered what the machine will be used for and determined whether you really need speed or just something that is able to run things correctly. The next thing to consider is are the programs you use properly multithreaded. Multithreading is when a program uses more than one core of the processor. For a long time, games were only using two or in sometimes four cores, but we are slowly moving beyond that. No matter what your task, it is valuable to look around the forums for that software and try to find out if it would even use the extra cores if you are deciding between two different core count options. Keep in mind that your machine will be able to do other concurrent tasks better if you have more cores, but you may not get any benefit from some of the apps you are using simply because you have more cores. If the biggest thing you are worried about is encoding a video using some software and you see that that software doesn't seem to get a proportional gain to the increased core count then it may be better to look at a different option or just go for the lower core count model.

GHz Race

One of the most common determiner's of speed in days old was GHz. This used to be a pure metric on how fast the processor would be, but now we have so many different models and architectures and manufacturing nodes that you can't simply say that a 3.2GHz chip beats a 2.8GHz chip. Instead, now, a user must simply look at benchmarks and see how an individual processor performs a task because the GHz number does not mean a whole lot. If a processor is of the same generation and the same series and has the same amount of cache (this is basically really fast on-processor RAM) then you may look at GHz as an indicator, but for the beyond that it is really best to simply view benchmarks. Anandtech and Tomshardware are great places to start with these. Processors these days simply have too high of a range of IPCs(Instructions per cycle, basically how fast a processor is in reference to it's GHz). That being said, there is still plenty of room to optimize purely on GHz. Like I said previously, a software may not benefit from increased core count, but it likely does benefit from an increased clock speed. In certain tasks, like gaming, that is why a $300 6700k with 4 cores will almost always outperform the much more expensive 10 core $1700 6950X. The games cannot efficiently take advantage of the additional threads, but they can take advantage of the higher clock speed.

TDP (Thermal Design Power)

TDP or thermal design power is, for our purposes, at least, the amount of power that the processor uses and heat it puts out.  This something else to consider when picking your processor. This number has slowly crept down over the years as manufacturers have made more efficient processors, but it is still not insignificant. If you are in a small enclosed room you can definitely increase the ambient temperature by a few degrees if you have a high wattage processor and you run it for full tilt for a while. In many places, the electricity cost is negligible even across an entire year of usage, but it does add up in places with high electricity costs. If you want to see a quick estimate of what a difference between two different wattages of processors will cost you can visit this site and enter in the different wattages of the processors you are considering and your electricity cost and your estimated usage. One other thing to consider is that if you are going to run the AC to counteract the increased temperatures in your room you will actually be paying double for the increased wattage. If this is something you are concerned about then you might want to consider a processor that ends with "T" in the model name. These are Intel's low wattage variants and they have some chips there that perform just as well as their higher wattage siblings.

Summary

Overall, what I want you to take from this article is that there are a lot of things to look at with processors, but ultimately it comes down to meeting your needs in the most efficient way possible. Don't come into this process with a set number in mind and instead try to find the correct tool for the job. Figure out what the expected usage is and whether or not the applications you use would benefit from more cores or if they really need higher clock speeds or higher IPC. Then consider if you are in an environment where TDP is important to you or if there is a variant that will save you money on electricity and AC costs while still meeting your needs. If you follow this framework you will likely find you can make a better decision.

What to look for when checking compatibility of a processor

Picking out a processor can be a difficult task. There are many different aspects you need to look at in order to make sure a specific processor will work with your system. Sometimes the documentation is incomplete or you can't find it. Sometimes there is just some weird combination of factors that make things not work and sometimes the information straight from the manufacturer is simply incorrect. In this guide, I am going to explain to you how to sift through the information so that you can determine whether or not a processor will work in your system. In the end, it is very simple. There are only really 4 factors for most modern systems, even less if you are using desktop parts. The factors are socket type, processor generation, motherboard chipset and BIOS revision (and memory type if you are on a server).

Socket Type

This, in the past, was the simplest of aspects to look at when determining a processor for a system because it is essentially just like when you played with blocks when you were a kid and needed to put the correct block in the same hole. This has been complicated in recent years because both Intel and AMD have decided to use very similar socket types across a few generations of processors and only swap out one or two pins or upgrade a chipset without changing the socket. This means that nowadays a processor may still fit in the socket but is still not compatible. This is still the simplest way to quickly disqualify many processors from your potential hunt. Simply put, if a processor has a different socket type from your motherboard then it will not work for you( excluding rare cases like where you can use an LGA775 to LGA771 adapter).  There are two quick and easy ways to check the socket type of your motherboard. The first is to go directly to the manufacturer and go to their support area and search up your motherboard or desktop. If you are unsure of what model you have you can use our tool to look up your motherboard or desktop model and then look at the manufacturer's website with that information

Another option is to find the socket type directly by downloading a tool like CPU-Z and letting that do a quick scan of your system. 

Once you have found which socket your motherboard has you can start looking at potential processors. One option, if your motherboard uses an Intel processor, is to check the Intel ARK. This website is Intel's official knowledge base which holds just about any processor information you could possibly want. You can do a simple search in the top right for your socket and it will tell you all of the processors that will fit in your socket. This does not guarantee compatibility with your specific system, but it is a start.

If you do not have an AMD motherboard or you could not find any results for your Intel motherboard on the ARK then you can also use a similar tool found at CPU-World. Just find the Socket Type option and then select "contains" and then type in your socket type. After this initial search, you may need to do another search by selecting from a list it gives to you to narrow down the results to your specific socket, but after you do that it should give you a list of potential matches exactly like the Intel ARK.  Now you have a list of potential candidates so we can move along to processor generation and motherboard chipset.

Processor Series and Motherboard Chipset

These two next factors go hand-in-hand because generally a new motherboard chipset is released with each series of processors and a processor released with that chipset will be compatible in almost all cases. In the past, it was easy to determine the processor compatibility by looking at the first number of a part number, but recently this has become an unreliable method. For example, relatively recently, Intel released the 4770k and the 4930k at the same time so you would think that they would both work in the same motherboards, but, in fact, they do not even use the same sockets and are incompatible. For a 4930k you need an X79 motherboard and for a 4770k you need a Z97 motherboard. This is why it is dangerous to just look at the leading number. It is best to look at the processor series. In the previous example, you could look up the 4770k and find it was a Haswell processor and then with a search on the Intel ARK you could find a list of the compatible chipsets. To find out which chipset your motherboard uses you can look at the support site from the manufacturer of your desktop again or use CPU-Z again. Many times you do not even need to use these resources if you already know the name of your motherboard though because often the chipset is in the motherboard's name. For example, ASUS Z170-A LGA 1151 Intel Z170 HDMI SATA 6Gb/s USB 3.1 USB 3.0 ATX Intel Motherboard. This tells you in the name that it is a Z170 motherboard and it has an LGA 1151 Socket. 

BIOS Revision

The final factor to look at is the BIOS revision. This is a commonly overlooked factor but can often be a huge frustration point that many people forget about or did not know about in the first place. To simply explain what the BIOS is for those who do not know, it is basically the hardware level settings for everything plugged into your motherboard. In order to run the processor you want, it must have a new enough processor microcode. The microcode is basically the directions for a list of processors and how to run them. If the BIOS does not have the microcode for your processor then it will not boot up because it doesn't have the proper instructions to initiate the processor. Luckily for you, the BIOS is updateable and if a processor comes out after a motherboard is released you can put a newer BIOS on your motherboard and then it will be able to accommodate the new processor. One thing to really emphasize though is that you must update the BIOS before installing the new processor. Some manufacturers now have a tool so that you may update the BIOS via USB without a processor installed but in many cases that may not be possible.

Now that you know all about what the BIOS is and what you can do with it I can talk to you about what you need to look at to confirm compatibility.  The first thing to do is to simply look at your motherboard or desktop manufacturer's website. Typically this information will be under support and then maybe downloads and then you will find various BIOS versions there. Some manufacturers will simply list out which processors are compatible and which aren't but for some you will need to delve into their documentation a little bit further. The document name I typically look for is Release Notes somewhere near the BIOS version. In these documents, you can find if there is a version of the BIOS which included an update to the microcode or added compatibility for a certain series of processors. If you find that the processor you want to use was added on by a BIOS update then you need to check for your BIOS revision and make sure it is newer than the required version to run the processor you want. You can find this in CPU-Z under the mainboard tab.

If your BIOS revision is not new enough then you will need to update it before you can use the new processor. You can either find the most recent version off of the manufacturer's website or you may use a tool like BIOS Agent Plus to find the most recent version for you and help you install it. It is very important to make sure that you follow any directions given to you very closely when dealing with the BIOS because you can easily brick your motherboard if you turn off the power when updating or if you update with the wrong version.

TDP( Total Design Power)

TDP is another thing that used to be an important consideration when looking at processors and motherboard compatibility but it has fallen by the waist side as systems have become more efficient and developed the standards to deliver adequate power. I figured it was worth to add in any way for those who may be using older systems. To explain for those who do not know what TDP is, it is basically the total wattage that the CPU will consume and then convert to heat. This is a particularly important consideration on all of the AMD processors because if you look at the highest end processors they have the FX-9590 has a TDP of 220W. This is a gargantuan number in comparison to most current processors and many motherboards likely cannot put that much wattage through their socket without melting their voltage regulators or frying themselves. For reference, 220W is likely more power than your entire system draws if you are on a modern system and do not have a high-end graphics card installed. If you have an AM2, AM2+, AM3, or AM3+ and are looking for compatible parts it is probably wise to also consider the TDP and see if there is any documentation along with your system that says specifically whether it can handle a 135W processors or just a 90W processor and you may also even want to look to see if your power supply can provide ample wattage. I have seen plenty of pre-built systems that have power supplies rated for 225 watts or less and if you plug an FX-9590 into one of those you would really be playing with fire.

Summary

To summarize, the first thing you should look at when looking for compatible processors is the socket type. If you do not have the correct socket type then the processor will likely not fit or the pins will not match up. After you determine that it is the correct socket you should look at the CPU series and compare it to the chipset series. There are plenty of resources online to make sure that your motherboard has a chipset that will likely be compatible with the processor you are interested in. Check Wikipedia or the Intel Ark and they will guide you in the right direction. After that, you should look at the manufacturer's website and see if the processor is listed in their documentation anywhere and if it is, does it require a new BIOS revision to run. These are the basic steps that I run through whenever I am uncertain about the compatibility of a processor. If you have any further questions about compatibility or have something you would like to add to this guide, please leave a comment and I will try to address it as soon as I can.

Bonus Cheat Sheet

Dell PowerEdge T630 Tower Server

The Dell PowerEdge T630 is a Tower based server that has the ability to be converted into a rackmount server when a mounting bracket and rails are installed. It features a proprietary Dell motherboard which is run by an Intel C612 series chipset (Desktop Similar is the X99 Chipset). This allows for dual Haswell-EP (E5-2600 v3 series) processors or Broadwell (E5-2600 v4 series) processors (If BIOS revision 2.1.5 or newer is installed) and 24 slots for DDR4 RDIMMs or LRDIMMs

When running BIOS revision 2.1.5 or newer the maximum addressable memory for a single socket configuration is 1536GB with Quad or Octo Rank Load-Reduced DIMMs. With a dual processor configuration, this figure is doubled to 3072GB. This is using 24 of the recently released 128GB LRDIMMs. If using a revision older than 2.1.5 then the maximum addressable will be 768GB in a single socket configuration or 1536GB in a dual socket configuration. This is achieved using 24 64GB LRDIMMs. Of note, you cannot utilize 128GB DIMMs until the BIOS is updated and you may not use the memory slots assigned to a non-populated processor. To explain further, you cannot achieve the 768GB single processor maximum by using 24 32GB DIMMs because 12 of the slots are associated with the empty processor socket. The memory can operate at 2400MT/s in all configurations and ranks except for triple channel configurations. With RDIMMs the maximum then becomes 1866MT/s in triple channel and LRDIMMs can still operate at 2133MT/s in triple channel

There are many storage configurations for the Dell PowerEdge T630. One option is 32 2.5" drives without the flexbay or 18 2.5" with the flexbay.  Another option is 18 3.5" drives without the flexbay or 8 with the flexbay. The flexbay is essentially a riser card that allows the install of PCIe SSD cards in the front or additional hard drives or solid state drives.

There are a few known issues with the T630 that have been addressed with BIOS updates. The most major being users experiencing the red screen of death (RSOD) when using the E5-2603 or E5-2609 processors and performing a reboot. This was remedied in BIOS revision 2.1.5 so if you are using this configuration it is highly recommended you upgrade.