Upgrading from an Intel Core i7-2600K: Testing Sandy Bridge in 2019
by Ian Cutress on May 10, 2019 10:30 AM EST- Posted in
- CPUs
- Intel
- Sandy Bridge
- Overclocking
- 7700K
- Coffee Lake
- i7-2600K
- 9700K
Power Consumption
One of the risk factors in overclocking is driving the processor beyond its ideal point of power and performance. Processors are typically manufactured with a particular sweet spot in mind: the peak efficiency of a processor will be at a particular voltage and particular frequency combination, and any deviation from that mark will result in expending extra energy (usually for better performance).
When Intel first introduced the Skylake family, this efficiency point was a key element to its product portfolio. Some CPUs would test and detect the best efficiency point on POST, making sure that when the system was idle, the least power is drawn. When the CPU is actually running code however, the system raises the frequency and voltage in order to offer performance away from that peak efficiency point. If a user pushes that frequency a lot higher, voltage needs to increase and power consumption rises.
So when overclocking a processor, either one of the newer ones or even an old processor, the user ends up expending more energy for the same workload, albeit to get the workload performed faster as well. For our power testing, we took the peak power consumption values during an all-thread version of POV-Ray, using the CPU internal metrics to record full SoC power.
The Core i7-2600K was built on Intel’s 32nm process, while the i7-7700K and i7-9700K were built on variants of Intel’s 14nm process family. These latter two, as shown in the benchmarks in this review, have considerable performance advantages due to microarchitectural, platform, and frequency improvements that the more efficient process node offers. They also have AVX2, which draw a lot of power in our power test.
In our peak power results graph, we see the Core i7-2600K at stock (3.5 GHz all-core) hitting only 88W, while the Core i7-7700K at stock (4.3 GHz all-core) at 95 W. These results are both respectable, however adding the overclock to the 2600K, to hit 4.7 GHz all-core, shows how much extra power is needed. At 116W, the 34% overclock is consuming 31% more power (for 24% more performance) when comparing to the 2600K at stock.
The Core i7-9700K, with eight full cores, goes above and beyond this, drawing 124W at stock. While Intel’s power policy didn’t change between the generations, the way it ended up being interpreted did, as explained in our article here:
Why Intel Processors Draw More Power Than Expected: TDP and Turbo Explained
You can also learn about power control on Intel’s latest CPUs in our original Skylake review:
The Intel Skylake Mobile and Desktop Launch, with Architecture Analysis
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cwolf78 - Friday, May 10, 2019 - link
Is there any way you can do a similar comparison with the i5 CPUs? I have a 3570k OC to 4.2 GHz and its starting to struggle in some games. E.g., I can get over 60 fps in AC Odyssey for the most part, but there's all sorts of annoying spikes where the min FPS will tank for whatever reason. I'm running a GTX 970 that's OC'ed pretty close to a 980 and I don't know if it would be worth upgrading that or if my CPU would strangle anything faster. Also, whats the performance difference between an OC 3570k and a OC 3770k in modern games?RSAUser - Saturday, May 11, 2019 - link
This is mostly due to being 4 threads, that's also why I wouldn't go with anything <8 threads as you'll see it happen more and more as we all move to higher core counts.Plus Ubisoft has probably got the buggiest/worst optimized games, last one I can think of that was all right was Black Flag, mostly because they didn't change the engine and just changed the story line/map.
uibo - Friday, May 10, 2019 - link
At what voltage did you run the 2600k?abufrejoval - Friday, May 10, 2019 - link
I owned pretty much every iteration of Intel and AMD since the 80286. I pushed them all on relatives and friends to make space for the next iteration.But everything since Sandy Bridge stuck around, both because there was no reason to move them out and I had kids to serve. Mine was a 2600 no-K, because I actually wanted to test VT-d and for that you needed to use a Q-chipset and -K was not supported.
Still drives the gaming rig of one of my sons, while another has the Ivy Bridge (K this time but not delivering beyond 4 GHz). Got Haswell Xeons, 4 and 18 core, a Broadwell as Xeon-D 8 Core, Skylake in notebooks and Kaby Lakes i7-7700K in workstations and an i7-7700T in a pfSense.
Those newer i7s were really just replacing AMDs and Core-2 systems being phased out over time, not because I was hoping for extra performance: AT made it very clear for years, that that simply won’t happen anymore with silicon physics.
What I really wanted from Intel, more cores instead of a useless iGPU, more PCIe lanes, more memory channels I eventually got all from the e5-2696v3 I scored for less than $700 on eBay.
Zen simply came a little too late, a couple of Phenom II x4-6 and three generations of APUs taught me not to expect great performance nor efficiency from AMD, but at least they were budget and had become reliable (unlike the K2-K3+s).
With the family all settled and plenty of systems in all sizes and shapes the only reason to buy CPU any time soon would be to replace failed parts. And fail they just don’t, at least not the CPUs.
And then I must have 100GB or so in DDR3, which I really don't buy again as DDR4 or 5. DDR3-2400 is really just fine with Kaby Lakes.
I overclocked a bit here and there, mostly out of curiosity. But I got bitten far to often with reliability issues, when I was actually working on the machines and not playing around, so I keep them very close to stock for years now: And then it’s simply not worth the trouble, because the GPU/SSD/RAM is far more important or nothing will help anyway (Windows updates…).
Nice write-up, Ian, much appreciated and not just because it confirms my own impressions.
WasHopingForAnHonestReview - Friday, May 10, 2019 - link
Nice reply. Thanks. My 2600k is just cranking along as my darknet browsing machineRSAUser - Saturday, May 11, 2019 - link
The Zen chips actually have pretty good efficiency, I was expecting way worse before it came out since AMD hadn't been competitive in years. Zen 2 will be quite interesting, mostly due to the node shrinkage hopefully bringing way lower power envelopes and maybe cheaper CPUs, since we all need that saving for the mess that the GPU market has become.Targon - Tuesday, May 14, 2019 - link
Don't discount the significant IPC improvements that are expected from the third generation Ryzen processors(not the APUs which are Zen+ based from what I have read).evilspoons - Friday, May 10, 2019 - link
Still have a 2600k at 4.6 GHz with proper turbo support (slows down when idle). Went from GTX 680s in SLI to a single GTX 1080 and it plays most games just fine.That being said I'd love to throw in a Ryzen 7 2700X but only if one of you pays for it... 😁
rocky12345 - Friday, May 10, 2019 - link
Nice flash back review thank you. I am still on a i7 2600K@5.1GHz with 32GB DDR3@2400MHz and very tight timings. It took a while to dial in the memory since Sandy does not really support this speed gracefully like it's newer brothers & sisters do. I have 2 Samsung 512GB SSD drives in raid zero so plenty fast for windows drive and some games installed as well as 2 4TB 7200RPM hard drives.I think some of the issues you were having with the OC 4.7GHz was probably do to either memory not 100% stable or the CPU may have just been at the edge of stable because it probably wanted just a tad bit more voltage. on my system I had random problems when it was new due to memory timings and finding just the right voltage for the CPU. After getting all of that dialed in my system is pretty much 100% stable with 5.1GHz and DDR3@2400MHz and has been running this way since 2011.
So going from these charts for the gaming results & mine at 5.1GHz would place my system faster than the i7 7700K stock and a slightly over clocked one as well. Though I am 100% sure a i7 7700K fully overclocked would get better FPS since their IPC is like what 10%-12% better than a Sandy clock for clock and then if you throw in AVX2 My Sandy would get hammered.
I am going to be upgrading my system this summer not because I feel my system is slow but more because I know because of it's age that something could fail such as main board or CPU and it would be costly to try to replace either of those so time for the big upgrade soon. I probably will move this system to do secondary duties and have it as a back up gaming system or there for my friends to use when we get to together for a gaming session. I have not fully decided which way to go but am leaning towards maybe AMD Ryzen with Zen 2 and at least 8/16 CPU and maybe a 12/24 CPU if they release more than 8 cores on the main stream desktops.
isthisavailable - Friday, May 10, 2019 - link
Still running a i5 3450. Runs fine and maintains 60 FPS for 95% of the time.