No announcement yet.

Revit Hardware : CPU

This is a sticky topic.
  • Filter
  • Time
  • Show
Clear All
new posts

    Revit Hardware : CPU

    Hi all - as of 2019, I'm no longer updating these hardware threads (unless there's a major change in technology or the way Revit utilizes hardware). The details, model numbers, CPU/GPU names, etc. may be slightly different, but the concepts are still the same. Still feel free to post questions or comments in this thread.

    I've attempted to write this series of posts in a way that will be accessible to everyone. It may seem a little boring and geeky, but you'll be better prepared in making purchasing decisions, or when asking questions or for advice. Also please note that the recommendations given here for specific products are not exclusive - there are too many usage scenarios to cover every option.


    Revit performance is very dependent on a fast CPU. It can not be stressed enough - the faster the better!

    There are two CPU providers for PCs that run Revit: Intel and AMD.

    Intel owns the upper end CPU market these days, and you'll want an Intel CPU for running Revit. There are two main "brands" of Intel CPUs: "Core" (i9/i7/i5/i3) and "Xeon".

    Intel Core i7/i5/i3
    Currently your best bet for maximum performance is the most current generation Intel Core i7 (or equivalent Intel Xeon). The Intel Core i5 will work fine as well, though the cost difference is negligible (at least in most parts of the world), so stick with the Core i7 if you can. While the Intel Core i3 will run Revit, it's a budget CPU that really isn't appropriate for a Revit workstation. The i9 is part of Intel's high-performance platform offering additional cores. Note that for laptops, CPU performance even at the high-end cannot quite match the fastest desktop CPUs, so while laptop versions of the i7/i5 can certainly offer excellent performance, there is a tradeoff for the portability.

    The recommended current crop of Intel Core and Xeon CPUs are often referred to as "Coffee Lake" (i7-8xxx), "Kaby Lake" (i7-7xxx). The older "Skylake" (i7-6xxx) are still great CPUs as well.

    Intel Xeon
    The Xeon is marketed toward the "workstation/server" market. However, that does not mean it's "better" for running Revit. Just like all CPUs, Xeons come in a variety of different speeds. They are inherently no faster or more stable than their Core counterparts, and in many cases, they are nearly identical parts.

    The only important distinction (as it relates to Revit) is that some Xeons are dual CPU (socket) capable, which means you can have two CPUs in the same computer, effectively doubling the number of cores (more on "cores" below).

    Intel released its very first Xeon laptop CPU toward the end of 2015... there are a few laptops out there that use it, but it really doesn't offer any performance advantage for Revit.

    Intel Skylake-X
    Intel markets a number of desktop i9/i7 "X" ("Extreme") CPUs (and equivalent Xeons). The main advantage over their standard Core brethren is that they offer up to 18 cores under the "Core" brand, and even more than that under the "Xeon" brand. Here's the rub though - in most instances you'll actually be better off sticking with the newer and more affordable Coffee Lake CPUs (the "X" variants are generally about a generation or two behind the standard i7 variant). The primary reason to use these instead of the regular i7 is if you really need a lot of physical cores or multiple graphics cards for GPU rendering.

    AMD recently (i.e. 2017) got back in the game with their "Ryzen" CPUs which sport lots of cores at a lower price than Intel. However, while they may be a great value, Intel retains the performance crown. Nothing wrong with them, and AMD fans will be happy.

    GHz (Clock Speed)

    CPU's clock speed is generally measured in GHz (gigahertz), as in 2.8 GHz. In very simple terms, the higher the clock speed, the faster the CPU. Therefore, clock speed is the most critical aspect of CPU performance.

    However, clock speed is very relative - it's not always comparing apples to apples. You can generally only compare clock speed as a measure of performance if you're comparing CPUs of similar generations (e.g. a Kabylake i7 @ 3.0 GHz with another Kabylake i7 @ 2.4 GHz). That point is critical when looking at a CPU's clock speed. For example, the latest generation Core i7 @ 2.4 GHz is probably 100% faster than the now ancient Core 2 @ 2.4 GHz. Even though they both have the same GHz clock speed, the i7 has a far more advanced CPU architecture that allows it to process far more data at the same clock speed.


    Almost all modern CPUs come with multiple cores in a single CPU. Each core is a little bit like it's own CPU. Generally the more cores, the better, especially for tasks such as rendering views. However, Revit still uses only one core at a time for most tasks, so it's important that no matter how many cores the CPU has, the speed when using a single cores should be very fast. As an example, you'd be better off for most Revit tasks with a Core i7 dual core @ 3 GHz, rather than a Core i7 quad core @ 2.5 GHz. However, when rendering, that same 2.5 GHz CPU will outperform the 3 GHz version because it has twice as many cores, e.g. 2 x 3GHz = 6GHz which is less than 4 x 2.5GHz = 10GHz.

    Intel Turbo Boost

    Turbo Boost allows most current Intel CPUs to dynamical increase the CPU's clock-speed to a higher number when needed.

    Having Turbo Boost is a huge advantage, and it's critical to understand what the Turbo Boost speed is when evaluating a CPU. This is especially true with laptop CPUs because sometimes the base core clock speeds are set very low to conserve power, but have very high Turbo Boost speeds.

    For instance, the i7-4900MQ (a laptop CPU) only has a base core speed of 2.8 GHz, which might at first glance seem quite slow compared to some desktop CPUs, but it can actually boost up to as high as 3.8 GHz using Turbo Boost.

    Another example, the Core i7-4770 (used in desktops) is a quad core CPU, and has a base core clock speed of 3.4 GHz. However, the CPU can boost to 3.7 GHz even when using all 4 cores, and 3.8 GHz when using 2 of its cores, and 3.9 GHz when using only 1 of its cores.

    Wikipedia is a good resource for Intel CPUs and their Turbo Boost speeds (links provided at the end of this post).


    Hyper-threading in Intel processors means that the OS (i.e. Microsoft Windows) can schedule two data threads simultaneously. If one thread stalls, the other thread can be processed instead. It's is not quite like getting twice as many cores, but it does allow the CPU to process multiple threads more efficiently, and can be a significant boost for tasks such as rendering. Almost all i7 CPUs have Hyper-threading, which is one of the main advantages over the i5 which generally doesn't have Hyper-threading.


    Cache is a relatively tiny amount of memory integrated into the CPU. The cache improves performance - the more cache the better (also, the more cores a CPU has, the more cache it needs). It's one of the reasons the i7 CPU generally performs better than the i5 CPU. However, don't get hung up on it, or use it as a way to evaluate performance by itself. You should almost always take higher clock speed over more cache.


    I'm a bit reluctant to even mention over-clocking, but it gets brought up in the hardware forums so often, I'd be remiss not to. Over-clocking (or "OC" and its derivatives) is the practice of increasing the clock-speed of the CPU (or other parts of the computer such as memory or the GPU) above the original manufacturer's specification to boost performance. This is analogous to customizing a car engine to produce more horsepower. The upside is that you can get more performance for "free". The downside is that you can end up with an unstable or fried computer.

    For most "business" environments, the benefits do not outweigh the potential issues. Traditionally, OC was only done on custom-built computers by computer hobbyists, but recently more pre-built OC systems are available, and the technology has become much more accessible. Intel even "encourages" it to some extent (though cynics would suggest Intel sells more CPUs that way since over-clocked CPUs tend to have a shorter lifespan
    ). Generally speaking, laptops cannot be OC'd. The overall topic of over-clocking is too extensive to cover here, and is well covered on many computer enthusiast websites. It's easy to get the impression that "everyone is doing it", but in reality, OC makes up only a very small percentage of computer usage.


    There are a number of benchmark lists available on the web that indicate the performance of various CPU's. Also check out RFO's Gordon Price's Benchmark threads in this forum.

    Just note that when evaluating any reported benchmarks, it's critical to understand what the benchmark is measuring. Some benchmarks measure how fast the CPU is when using only one of its cores (often noted as "single threaded" or "single core"), while other benchmarks measure the CPU when using all of its cores (often noted as "multi-threaded" or "multi-core"). Also note that some benchmark lists include overclocked CPU's that may indicate greater performance for a CPU than is typical. The amount of performance differences between CPUs can also depend on what kind of software is being benchmarked. So treat benchmark charts only as a guide.

    The Present, Past & Future

    We all know how fast technology becomes outdated. If you're considering purchasing new hardware, and you like to have the latest and greatest, this is what you should know:

    "Coffee Lake" is the newest, and started to trickle out in late 2017. Coffee Lake is just a slight refresh of Kaby Lake, which is also still considered current. Neither really doesn't offer much in the way of performance advantage over Skylake (which proceeded Kaby Lake), so don't feel like you've got to get the latest if you're looking to purchase a new system.

    "Skylake" was officially launched in 2015 and is still used in many current computers. "Skylake" is the successor to Broadwell/Haswell.

    "Cannonlake" will be the successor to Coffee/Kaby Lake, and is due later in 2018 or possibly even early 2019 (after originally being scheduled for 2016, it's been delayed several times).

    Frequently Asked Questions

    "Are Xeon CPUs better for CAD workstations? I've heard they're faster and more reliable."
    No, Xeon CPUs are not better for Revit, and they are not inherently faster or more reliable. Xeon is just an Intel brand, one they've been using for over a decade. The current generation of Xeons are almost identical to the current generation of i7/i5 counterparts.

    Sometimes the Xeon-based workstations offered by Dell, HP, etc., have a better build quality than their consumer-oriented products. Also, Xeon CPUs offer something called ECC RAM support which theoretically can offer greater stability for certain applications, but it's not really applicable to your typical CAD workstation (i.e. ECC RAM is of little benefit to an application like Revit). These points sometimes get misunderstood as Xeon's being more "reliable", etc.

    "Does Hyper-threading double the amount of cores?”
    There's often a misconception that Hyper-threading is like doubling the number of cores on the CPU. It doesn't quite work that way. Sometimes it barely increases performance, and sometimes it can drastically increase performance, it just depends on the task the CPU is performing. It's particularly useful in rendering.

    "Can Hyper-threading actually slow down the computer?”
    In some very rare instances, Hyper-threading can actually reduce performance very slightly in specific circumstances. However, on balance, disabling Hyper-threading will hurt overall system performance, and significantly reduce performance in certain tasks. It's strongly recommended to leave Hyper-threading enabled (Hyper-threading is always enabled by default in the computer's BIOS settings).

    "How much cache should I have on my CPU?”
    There isn't a certain amount you should get. Faster CPUs generally have higher clock speeds and come with more cache. However, lots of cache by itself doesn't make a CPU fast. As an extreme example, the Xeon e5-2650 has an astounding 20 MB of cache but only runs at 2 GHz. An i7-3770 (3.4 GHz) has "only" 8 MB of cache but will clobber that Xeon at most Revit tasks.

    Bottom Line

    Get the fastest i9/i7/i5/Xeon CPU you can afford.

    "Coffee Lake", "Kaby Lake" or "Skylake" Intel Core i7 (or Xeon equivalent). The Intel Core i7-8700K (Coffee Lake) is the one to beat, but the i7-7700K (Kaby Lake) and i7-6700K (Skylake) are still solid if you can't get your hands on the 8700K (the "K" versions are desired, but the non-"K" versions are 95% as good). If you're looking at Xeon, look for the Skylake Intel Xeon E3-1280 v5.

    "Kaby Lake" or "Skylake" (at the time of this writing, Coffee Lake mobile CPU's haven't been released yet). Try to get one with a minimum 2.6 GHz base clock speed, with Turbo Boost to at least the 3.5 GHz range (laptops often have much lower base GHz clock-speeds than their desktop brethren, but they generally have very high Turbo-boost numbers). The Intel Core i7-7700HQ (or better) and i7-6700HQ (or better) are highly recommended. If you need a ultraportable/tablet-based laptop, the CPU (and likely graphics) won't be optimal for Revit, but may be adequate for light-duty in-the-field usage.

    I know all these code names and numbers will make most users brain explode, so if you're confused, just post your question on the forum! Also, keep in mind that this article is aimed at professional usage; students or part-timers on a more limited budget will generally be fine with little less.

    Additional Resources (Wikipedia)

    List of Intel i9 CPUs

    List of Intel i7 CPUs
    List of Intel i5 CPUs
    List of Intel Xeon CPUs
    List of AMD CPUs


    I've been a computer enthusiast for over thirty years. I know a lot, but I don't know everything. Drop me a PM with suggestions, or if you spot any errors, or think something needs further clarification, or feel free to take it up with me in the forums. And please *post* those questions, requests for advice, and solutions!
    Last edited by Robin Deurloo; June 7, 2021, 08:10 PM.

    Any update to include the new Xeon Sandy Bridge?

    Thank you.

    P.S.: You can erase this reply.
    Revit Architecture 2013 Certified Professional


      Originally posted by lucis29 View Post
      Any update to include the new Xeon Sandy Bridge?

      Thank you.

      P.S.: You can erase this reply.
      No need to erase your reply... these hardware threads can now be considered "discussion" threads.

      Intel just released the Sandy Bridge Xeons last week. I believe these are single socket CPUs... no multi-socket's yet, AFAIK.


        Originally posted by iru69 View Post
        I believe these are single socket CPUs... no multi-socket's yet, AFAIK.
        Then why buy an E3-1280 ($600+) instead of an i7-2600k?
        Revit Architecture 2013 Certified Professional


          Indeed why? There is no reason from a user standpoint at all. BUT, companies like HP still push Xeon as "professional grade" on people who don't know any better. HP and Intel make more money, and that is about it. Oh, and some IT decision makers probably feel like they are covering their butts when they continue to waste company money this way. When something doesn't work they can say "Well, not my fault, we bought the "professional grade" stuff.

          Pragmatic Praxis


            Originally posted by lucis29 View Post
            Then why buy an E3-1280 ($600+) instead of an i7-2600k?
            I completely agree with what Gordon said. It should be noted that the E3-1280 is 3.5GHz (versus 3.4GHz for the 2600). Intel often charges an extra premium for the "fastest" version.


              True iru, but the E3-1270 is $50 more, and still has 3.4 GHZ. Also, are the Xeon's overclockable? If no, then the i7-2600K is definitely the way to go.
              Revit Architecture 2013 Certified Professional


                Nice resource for comparing CPUs' general performance:


                  Originally posted by truevis View Post
                  Nice resource for comparing CPUs' general performance:
                  Hi Truevis, that is a nice resource and thanks for sharing that. :thumbsup:

                  However, anyone looking at it should note two things:

                  1. the benchmark results are for all cores being used at once, e.g. a 6-core i7-980X will beat a 4 core i7-2600 even though each individual core of the 2600 is faster than the 980X. That's fine if all you do is renderings, but for most Revit tasks, the 2600 should be faster.

                  2. the benchmark results include overclocking of at least some sort. This is apparent when looking at the results of the i7-2600 vs the i7-2600K - the 2600K comes out noticeably ahead. Those are virtually identical CPUs, and should have identical benchmarks results. However, the 2600K is unlocked (i.e. overclock-able), so the only thing that accounts for the 2600K's better performance is that users are overclocking their systems and submitting the results - which skews everything.


                    What impact or benefit do graphic cards have. Is there any off-loading during rendering? Beyond running multiple displays as one in very high resolution like SLI or CrossFire would it improve performance on a single 25" - 32" 1080p monitor? I've seen rather humble video cards provide smooth scrolling but no one mentions the need for better cards, ... just bragging rights.

                    Other than a large expensive Solid State Drive (SSD) for the main system and apps, would a smaller, say 50 gig SSD, used as a temp/scrach or rendering drive be of any real help.


                    Related Topics