Why an Overclockable Core i3 Might Not Exist: The Supermicro C7H170-M and Intel Core i3-6100TE Review

So Why Do We Not See an Overclockable i3 CPU?

A lot of users interested in the story of whether overclocking is going to come back to the cheaper end of the Intel spectrum are users who were part of the culture that did the overclocking thing back in the Pentium 4 and Core 2 Duo era. Back then it was a miasma of anything goes, and competitions involving extreme overclocking with liquid nitrogen starting to get a foothold within the industry. I remember the reason I got into overclocking: I wanted the performance of the expensive part but only wanted to pay the price of the cheaper part. My gaming system at the time, an X2 4400+, got a severe beating. My graphics card, an X1900XTX, ran hot and eventually died a couple of years later. It wasn’t until I spent some of that student loan money on a Core i7 920 system that I felt I had performance under my belt, but I still overclocked it to within an inch of its life, along with my shiny new 4850 graphics cards.

Giving those processors a 30-50% boost in pure frequency felt like a major accomplishment – I had done something my LAN party friends had not done (well, most of them), and I was blitzing around as if I had spent 3x on my gaming PC. This was the hay-day of overclocking, when you could buy cheaper components and feel like a champion, as well as spot a noticeable difference in actual performance.

Fast forward ten years or so: I’m older, I’m wiser, I have a regular income, a family, and limited free time. Suddenly spending $50-$100 to jump from a low end to a mid-range processor, if it merits a return on my free time, sounds like a good investment. If I was in any professional career apart from this one, I might not have time to tinker with an overclock so getting something that works is more important.

However, there are two immediate people in my life that can directly benefit from overclocking, and I’ve mentioned them in previous reviews.

First is my younger brother: in his mid-late 20s, in the games industry as a QA, moving through his career track. He has some money to spend (he bought two pre-overclocked GTX 980s recently), but still wants to push a quad-core mainstream CPU beyond 4.4 GHz for a quicker response time so he can play, watch Twitch, and have a massive amount of background processes. As long as it is stable.

Second is my cousin-in-law: a 16-year old who splits his time between CS:Go and DOTA2 for the most part, as well as some free-to-play MMOs. His system is budget restricted, even when I threw a few parts his way. If overclocking a Core i3 was a thing when we put his system together, I may have put him on one, but I wasn’t keen on going the Pentium route just because of what he does with the system and the results in our Pentium review. In the end he has an AMD setup, slightly overclocked. No doubt it will be upgraded by the time he graduates; depending on if he wants a laptop or a new desktop.

While my younger brother could afford and sit happy with an i5-K, my cousin-in-law is in that ideal spot to start looking for something cheap he can push to the limit, and is about the same age when I started getting interested in hardware rather than just the games being played on it. Starting to overclock and learning about how hardware works became a quintessential part of who I am today – I wanted to understand exactly what was happening, what tools I needed, and why those tools worked. One poignant question to ask is if this entry into technology no longer exists without a price barrier, or does it need to exist?

The purpose of this review boils down to one question: can an overclocked i3 compare to a higher class of processor and save money? The answer to that is no… and yes.

Why Yes

One of the benefits of a highly overclocked Intel processor is responsiveness. As seen with both the overclocked benchmark scores of the Pentium G3258 and the Core i3-6100TE, when single thread performance is paramount it doesn’t matter if the CPU costs $72 or $472, as long as the IPC and frequency is there. The only problem is that the same argument can be made for the cheaper Pentium being overclocked over 4.4 GHz – if all you need is single threaded performance, then there’s already a product on the market.

Why Yes, sort of

Our gaming tests show that the overclocked Core i3 is within spitting distance of the Core i5 performance. At worst, with the GTX 980, we saw a 10-15% gap in the average frame rates in our high-end titles. For the cost of an extra $50-100, which equates to almost 100% of the value of a second i3, is it really worth going from 63 FPS in Grand Theft Auto with the i3-6100TE overclocked to 71 FPS on the stock i5-6600? Perhaps that money is better spent on moving up a GPU class. Also, doing the overclock pushed the minimum frame rate for GRID on the GTX 980 from 99 to 123 FPS, hitting a 120Hz marker for minimum frame rates. That’s something to be interested about. Then when we moved to AMD and the R9 290X, the results were even closer between the overclocked i3 and the stock i5. The Core i3 part though never really matched the Core i5, meaning that if there was a 20% gap between the i3 and the i5 at stock, the overclocked Core i3 would be good to fit in the middle between the two:

Why No, sort of

A big question mark in gaming is DX12, and because of the lack of real world DX12 benchmarks in play right now (AoTS is still beta, 3DMark is synthetic), we’re not sure how it would play out. Using DX12 has both a pull and a push factor. With the right code and engine, using DX12 properly can pull low-performance hardware into something reasonable, and it can push high-performance hardware into something magical. If anything, while both sides of the coin are increased, it is difficult to determine if the gap (measuring FPS vs quality) between the two will close or widen. It will mean that low-end overclock systems can do more, but it will depend on if CPU throughput is the limiting factor in the game engine. One of the benefits of having more cores, and more cache per core, is that when CPU load is high there is less time spent fetching data from main memory, which puts a serious plug on performance.

Why No

This point latches on to the last sentence: there are some situations where having more physical cores is a tough barrier to beat. DX12 might expose this a bit more in time, but in a large number of our CPU benchmarks that had some form of variable threaded workload, most easily favored the i5 as the threads did not have to share registers or cache within an individual core, allowing the instruction flow to be singularly focused. When a single thread can fill the instruction buffers, HyperThreading has a negative response due to increased memory transactions to slower memory.

The Good Old Days

So while I may wistfully talk about how ‘overclocking was in the good old days’, it is clear that the landscape has changed significantly. A decade ago we were overclocking on processors with either one or two cores, doing that overclock gave a significant improvement in many areas. Now we have four threads on tap, and despite the nature software changing as well, it means that background processes no longer interfere with single threaded code or multi-threaded software can take advantage of the new microarchitectures and hide the older bottlenecks.

Overclocking clearly has its place, but it is obvious that the place it held a decade ago has shifted. Previously it enabled better multi-tasking and raised the ceiling on basic tasks, allowing users to save money on their purchase if they were willing to tweak some options and keep an eye on cooling. Today that ceiling is already high, and given that Intel only sells two high-end K processors for the mainstream segment, overclocking is relegated to the performance junkie with a large budget, unless you want to try your luck with a motherboard that might enable non-K overclocking. But that’s the thing – anyone interested in peak performance wants to take the best and go further, not necessarily take the low end and push it into mid-range.

The Gaming Market, and Overclockers

I’ve always been a big advocate of focal marketing. If you want to sell a product, there is no point in marketing it to the wrong audience (the whole concept of influencers or halo products/Top Gear is another topic I won't discss here). One metric I like to showcase is one derived from market observations: PC gaming can be broadly defined into two categories.

The first is the under-25s: either still in school or starting their first job, they might not be earning much or saving an allowance. These users are more likely to spend sub-$1000 on a gaming PC and play eSports titles (CS:Go, DOTA, LoL, Rocket League), sometimes looking at the triple-A titles at medium settings with their 1080p panel.

The second is the over-25s: In their first graduate position, or on their second or third job or promotion, perhaps with a family, but like to spend their spare earnings or bonuses on their hobbies. These are the users that might spend over $1500 on a gaming PC, and transition from the sub-$1000 crowd and want something that will play triple-A titles bigger and better. They will go in at the i5 or i7, perhaps a GPU or two and an SSD with a high end monitor. This is also the crowd currently looking at PC-based virtual reality.

Currently, it is the latter crowd that can afford the hardware to overclock, however most of these users would have been in the first crowd when they learned about overclocking. While the Pentium exists, the lack of a Core i3 might mean that fewer younger gamers venture into hardware enthusiasts, and instead just buy that pre-overclocked system when it comes time to get a PC for VR.

 
Core i3-6100TE at stock vs. Core i3-6100TE at 30% overclock

There’s something to be said about building a loyal consumer base, and an ideal way for Intel would be to rope in the younger crowd at Day 1, pushing them through until the big sales. That is how some of us late-20 and early-30 somethings, who are interested in overclocking and performance, came through the industry. But without competition, one might think that it’s not needed and you will buy the medium performance part anyway.

Non-K Overclocking: Xeons

For users reading this who are more interested in the professional side of the equation, it is time to talk Xeon. Having the ability to open up base clocking on casual Intel consumer parts would allow motherboard manufacturers to build the same technology into their Xeon platforms. Because Xeons are high margin, professional and have a focus on stability, it would perhaps be understandable why Intel would want to restrict overclocking such that the Xeons were not affected. We’ve spoken to several professional companies over the past year that say they have customers who want faster parts, they want an extra 10% on the base frequency, and they’re willing to pay increased service fees for it. The professional market (namely finance) still wants performance, but again there is no competition, so Intel already has your sale in the market which keeps their operating margins high. The question is at what price point you will have to enter as a result, and whether your software would have benefitted from a 4.2 GHz 10-core rather than a higher cost part with more cores but a slower frequency. If base clock overclocking transitioned into the Xeon space, I wonder how easily Intel would be able to close the gates if they wanted to.

There’s also the upgrade argument, which we are seeing play out in the consumer space. If one platform allowed overclocking, and you invested at that point, why would you need the latest two or three platforms if they didn’t allow you a performance advantage? This is potential lost sales.

Loop it back: Why Do We Not See an Overclockable i3 CPU?

The 1080p gaming tests show that an overclocked Core i3 can easily knock on the door of a stock Core i5 for $100 less, or the rough equivalent of another Core i3 sale. The situation is a little muddier on CPU benchmarks; with single-thread responsive getting a benefit but many workload based tests showed you need real cores to get a benefit. It doesn’t matter much at the higher end, where it won’t cannibalize sales, and it didn’t matter much on the overclockable Pentium where two threads and low cache were bottlenecks you can’t overcome.

So if you want that performance, you need to spend the extra money.

If it was a question of market share, we would see it added very quickly. But as it is not, it ends up being the difference between buying two chips or one from the same vendor – they would rather you buy two (or the equivalent of two) when there's no alternative.