i5-7600K vs i7-7700K + HT questions

[Max0r]

So for a new system which may be serving me for a long time into the foreseeable future (old system is many generations obsolete). I've narrowed my choice of CPU to two candidates: i7-7700K and i5-7600K.

My goal is a combination of maximum single thread performance and some decent level of multi-core performance without going far past $300. The i5-7600K would essentially function as saving a nice chunk of $ should I decide HT isn't worth it (especially if they can achieve similar clockrates). I suspect HT may bring more potential problems than it does potential performance.

1. How would the top-end long-term sustainable 24/7 overclocks compare for the 7700K and 7600K? Overclocking on air with a relatively powerful HSF combo, but no ultra-loud fans (moderately noisy is fine, example: under-volted high speed Delta tri-blade 120x38mm fans). I'm expecting ambient room temps in the 79°-81° F range typically, with reasonably good case flow (less powerful than the CPU fans).

2. Is the IHS likely to be a problem for maintaining any decent OC, perhaps over the long term? I've read many remarks about how bad the IHS can be on these things. I don't want to deal with de-lidding for the foreseeable future.

3. Does HT tend to significantly limit OC results?

4. How does HT overhead and HT enabling/disabling work? Some questions:
- Can HT only be enabled/disabled on all cores at the same time, or can it be enabled/disabled on an individual core basis?
- Can HT be toggled on the fly or does it require a reboot?
- Does HT overhead only apply when HT is being used on a specific core, or is there always overhead on all cores merely by virtue of HT being enabled?
- Can HT overhead be avoided on one core that's being used for a single thread app, but enabled on the other cores?

5. Can HT realistically provide more than a 15-19% potential performance boost to multi-thread processing? Are there any real world analogues to the 48% synthetics?

6. What benefits and problems have you experienced thanks to HT on any recent Intel quad+ core?

7. Are there any comparable CPU models I may be neglecting to consider for purchase? I've thought of, as an example, the Skylake analogues to these two models. I figured these newer ones would offer some better future-proofing on a platform/features level, but then again, maybe there is a better/cheaper selection of motherboards for the older ones. I will be investigating motherboards and RAM soon.

 

[EarthDog]

1. Ballpark the same.. sample dependent.
2. It will just limit the potential overclock. But you should see upper 4ghz easily.
3. Not on ambient. It generally wont overcome its(7600k) clock deficit though.
4. HT is on or off on all cores. Its changed in the bios and requires a reboot. Not sure what you mean by overhead...HT is always a slower than 'real' cores though.
5. Yes and yes. Reviews on the web.
6. None.
7. You can look at amd ryzen.. a bit slower ipc, but IF YOU USE the cores will perform better.

Personally, id keep out of the negligible minutia snag a 7700k...again, unless you actually have use for more than 4c/8t. But really, if you budget allows and your are keeping this for a while, a 7700k over 7600k is a no brainer.... or ryzen.

 

[trents]

If you game and want some future proofing then definitely go with the 7700k. More and more, games are beginning to transcend the four core limit so as to be able to take advantage of HT and that trend will only grow. Because of this you should look at Ryzen as ED said in his post. NewEgg has the 7700k for $305 this weekend which fits your budget. Really, there are no problems with HT that I'm aware of. Just makes a little more heat, that's all.

 

[||Console||]

Long term I would be looking at more cores/threads than four . So 7700k or r5 1600 .

 

[mackerel]

Even when HT is on, you can in effect run certain software as if it were off. Depends on the software and how much tinkering you do otherwise, but manually setting affinity such that in essence only one thread per core is used, it is like HT off.

For HT benefit, Cinebench R15 shows around 30% ball park improvement compared to without. I've also run some mathematical sieves and others which are also in a similar ball park. For closer to 50%, the last one I remember was LifeMapper distributed computing project but that hasn't been around for many years. I think I've seen other cases closer to 50% but I don't recall right now what they were. I think the Ryzen Blender demo was also a better case, but I can't find my results from that.

 

[SPL Tech]

1. Ballpark the same.. sample dependent.

Typically, the 7700k is around 200 Mhz lower than 7600k. Most users are around 4.7 - 4.9 Ghz. on the 7600k and 4.5 - 4.7 Ghz. on the 7700k. If he is planning on going air HSF and no deliding, anything over 4.7Ghz. is probably going to redline the temps. The 7700k produces more heat than the 7600k. Really, for maximum OC potential on the 7700k, if you're using air you really should be deliding. It's extremely easy to do (even with the razorblade), and it makes a massive difference. Deliding has more of a difference in temps than going from air to water.

I run the Evo 212 HSF with a single fan and with my chip being delided I can achieve the clocks in my signature with around 75-80c on benchmarking programs and in the 60s when gaming. If I had not delided, I'd be redlining the temps at 4.9 Ghz. It would probably be hovering around 95C for benchmakrks, so really at high OCs you really want to be deliding unless you're on water (which is a waste of money if you havent even delided yet).

Anyway, for the OP, whether the 7700k is worth it or not would be dependent on what he is planning on doing with his computer. If this is just a general purpose machine or light to moderate gaming, the 7600k is more than enough, especially with a solid overclock. If he is doing professional video encoding where he's encoding tons of video or he wants a top-tier gaming rig, then the 7700k would be better. I wouldent spend the extra cash for the 7700k though unless he is actually using aps that are CPU heavy on a regular basis otherwise you're spending extra money for something you're not really using. He mentioned single-core performance. You'd have to look at some benchmarks for the answer there. There are many out there. However I'd caution whether you are actually only using a single core like you think you are. Virtually every application out there will use multiple cores at this day and age. Even if the program is not written to take advantage of many cores, Windows has the ability to schedule processes on multiple core to balance workloads.

 

[EarthDog]

They are about the same, really. Sample dependent. At least at hwbot on air/water anyway...4.9/5 Ghz.

Remember, 4.5 ghz is the 7700k's turbo. If 4.5 is the minimum range, you didnt overclock.

 

[wingman99]

Depends on what you are going to do? I just purchased a i5 7600k for gaming and Video also other things that don't make a difference with more threads.

 

[Max0r]

Thanks a lot guys for your help so far. Single-thread is definitely the top priority as I'm primarily playing a couple old games that are either fully single thread or dual/semi-dual threaded, and they both have the potential to become quite demanding in certain situations, though I'm sure with one of these babies I'll rarely be hurting. These include WoW 3.3.5a with a bajillion addons (combine that with a 100-200 man world PvP war, Wintergrasp or Alterac Valley, to a lesser extent extremely high-DPS 25 man raids, though they probably wouldn't even touch the limit even on a lower end processor, though they will completely seize the game up on mine) and Diablo 3 (think 4 man clumping gobs of elite packs and mobs in 1 spot with multiple area damage dealers or just very calculation intensive layers of buffs/debuffs being interwoven into the incoming/outgoing damage, maybe it's not a big deal but I'd rather not chance it). Additionally, it seems single-thread is the bottleneck for many loading scenarios, instead of what media the data is stored on past 500-600 MB/s. This is sadly true for many games, it would appear. In particular, WoW 3.3.5a is massively CPU bottle-necked when reloading or quitting in the process of saving local addon settings, and the ability to quickly log off without forcibly terminating is an amazing tactical advantage in world PvP (alt-F4 initiates the logoff/save/exit sequence instead of simply terminating, so instead of leaving a passive toon waiting to get turned into a corpse you simply disappear, just wait for combat to drop momentarily) Then log right back on (again probably CPU limited in some stages) when your backup arrives and spam your invite/marking macro (this aint no game son!)

There will be times I encode videos and stuff, and record games, maybe even while streaming what I'm doing with a mic and camera, preferably in ~1920x1200 resolution or something similar. I suppose I don't need much CPU power to do a raw, relatively uncompressed video file dump of what I'm doing, but lack of HT/cores could definately hurt that later on when converting it. Thing is, I just don't think I'm going to have the time or resources to do this stuff much anyway, so I don't see the point of investing much into it. I would just do it once in a while. If I did have what I needed, I wouldn't be agonizing so much over $100

Ryzen definitely seems to obliterate Intel when it comes to bang for the buck multicore processing, but it just isn't getting there with the single threads sadly.

One thing which may or may not matter for HT, is that I do plan on having a lot of RAM, I guess 64 GB is the max for this platform, and having lots of stuff running at once, mostly for convenience. Dozens of browser tabs, possibly lots of which contain video and typical severely bloated websites. Encoding **** (could be deprioritized anyway). Video/audio recording ****. Audio conferences. Skype. Multiple clients of a single game. Maybe multiple games. And other crap. Will HT/cores matter for that? I'm thinking not. Even with the multiple games I don't care about the games running in the background performing well. Just that they don't disconnect/seize, or interfere with the foreground game. I'll only be focusing on one game instance at a time.

Anyone with experience running a mess of programs like that? Would HT actually matter (outside of squeezing more encoding performance)

 

[Max0r]

if you're using air you really should be deliding. It's extremely easy to do (even with the razorblade), and it makes a massive difference. Deliding has more of a difference in temps than going from air to water.

I run the Evo 212 HSF with a single fan and with my chip being delided I can achieve the clocks in my signature with around 75-80c on benchmarking programs and in the 60s when gaming. If I had not delided, I'd be redlining the temps at 4.9 Ghz. It would probably be hovering around 95C for benchmakrks, so really at high OCs you really want to be deliding unless you're on water (which is a waste of money if you havent even delided yet).

You're definitely making me strongly consider it, because I've seen the amazing difference it made with my Opteron 165 so I know exactly what you're talking about. My only concern is that there will be mounting issues requiring some sort of modification to a mounting bracket or something. If it's really easy to just razorblade that thing, that mounting issue is my 1 concern (and not getting too aggressive and cut-happy on the IHS )

What's the deal with mounting adjustments?

 

[trents]

They are about the same, really. Sample dependent. At least at hwbot on air/water anyway...4.9/5 Ghz.

Remember, 4.5 ghz is the 7700k's turbo. If 4.5 is the minimum range, you didnt overclock.

I agree with ED here. I would not say the 7600k typically overclocks higher than the 7700k as long as there is sufficient cooling.

- - - Updated - - -

You're definitely making me strongly consider it, because I've seen the amazing difference it made with my Opteron 165 so I know exactly what you're talking about. My only concern is that there will be mounting issues requiring some sort of modification to a mounting bracket or something. If it's really easy to just razorblade that thing, that mounting issue is my 1 concern (and not getting too aggressive and cut-happy on the IHS )

What's the deal with mounting adjustments?

When we talk about delidding we are not implying going "naked" with no lid. We rather mean to remove the lid, replace the poor quality thermal paste gunk that Intel uses these days with liquid metal TIM, and then putting the lid back in place. No mounting adjustments are necessary.

 

[wingman99]

HT will help a lot with streaming and encoding. I game and run my web browser with 50 tabs open, also watch videos at the same time with my 4 core i5 7600k. No deliding for me I have a 600MHz overclock from default Bios on air.

 

[Max0r]

Not sure what you mean by overhead

Read something somewhere about when HT is either enabled or being utilized on a core, part of its total processing capacity, perhaps as much as 10%, though that may be an exaggeration or extreme outlier scenario, is used for managing the HT, thus limiting single-thread performance on that core, or maybe all cores.

 

[wingman99]

HT technology.

 

[Max0r]

When we talk about delidding we are not implying going "naked" with no lid. We rather mean to remove the lid, replace the poor quality thermal paste gunk that Intel uses these days with liquid metal TIM, and then putting the lid back in place. No mounting adjustments are necessary.

Sweet! And that gets similar results as the naked procs of Yore? Dear god those stock TIMs must be horrible

 

[trents]

Sweet! And that gets similar results as the naked procs of Yore? Dear god those stock TIMs must be horrible

Yes it does. I've killed two expensive processors trying to go "naked" so I would strongly advise replacing the lid rather than going naked. The lid spreads out the pressure when you clamp the cooler on. Nowadays, they make these little tools to push the lid off the CPU rather than using a razorblade or wacking it in a vise like we did a few years ago. Believe me, get the $30 tool as it is well worth and virtually eliminates any chance of damaging the CPU while trying to remove the lid. http://www.ebay.com/itm/Intel-LGA-1...799788?hash=item33d25f672c:g:jsQAAOSw~rpZXnKn

The process involves removing the old gunky TIM and the glue around perimeter of the lid base that also probably creates a gap between the die and the lid. Some isopropyl alcohol and scraping with the edge of an old plastic credit card usually are sufficient to get all that junk off. There are plenty of online tutorials to help you delid and replace the TIM.

Most people delidding see 10-18c drop in max core temps under full load stress.

 

[Dermen]

There will be times I encode videos and stuff, and record games, maybe even while streaming what I'm doing with a mic and camera, preferably in ~1920x1200 resolution or something similar. I suppose I don't need much CPU power to do a raw, relatively uncompressed video file dump of what I'm doing, but lack of HT/cores could definately hurt that later on when converting it. Thing is, I just don't think I'm going to have the time or resources to do this stuff much anyway, so I don't see the point of investing much into it. I would just do it once in a while. If I did have what I needed, I wouldn't be agonizing so much over $100

If you are going to record games without a ton of compression Intel Quick Sync could work well. It uses the CPUs built in graphics to do encoding. At lower bitrates it doesn't have as good of detail as CPU encoding so it's not great for twitch streaming which makes it unpopular. At higher bitrates the quality is supposed to be fairly close to CPU encoding. It works well for making videos later. You record your play at high bitrate using little to no CPU resources, giving you higher fps. Later you edit and re-encode the video to a lower bitrate with the CPU. 7600k and 7700k support this.

Sweet! And that gets similar results as the naked procs of Yore? Dear god those stock TIMs must be horrible

For me delidding only got me another 100mhz with lower temps. You reach a point where you really have to start ramping the voltage up for small increases which increases temps fast. Delidding takes care of those temps but then you hit max vcore quickly.

My 6700k for example, before delid
4.5ghz 1.280v 86C
4.6ghz 1.312v 92C was not stable, too hot for me to push more vcore

After delid
4.5ghz 1.280v 65C
4.6ghz 1.328v 74C
4.7ghz 1.432v 87C too much vcore for me

The delid tools make it super easy and very low risk. I was able to borrow one, all it cost me was shipping.

 

[EarthDog]

Anyone with experience running a mess of programs like that? Would HT actually matter (outside of squeezing more encoding performance)

with your budget and long term use, a 7600k shouldnt be part of the conversation...more so from a keep it for years persepctive than your workload.

I also wouldnt worry about delidding either... most dont need it. That extra 100mhz really isnt worth much considering losing the warranty or the chance to kill it...or paying $30 for the tool amd $10 for paste....i dont think yoy are going to be in the benching team where every last mhz counts.

 

[trents]

Delidding can also give the benefit of being able to use smaller, less expensive coolers and to lower fan noise. It can really can make or break a mini ITX build where space is very limited and you have to use small cooling solutions, especially when overclocking.

 

[EarthDog]

It can no doubt. Tough call though... there are purpose built uses to delid, like (heavy) overclocking in an itx box, not many need to. Fewer id imagine would bork their warranty and (if needed) pay $40 more for delidding. Seems to be wash or net loss for a cheaper cooler having to pay out for the tool or paste for the delid. Iunno.