Sandy Bridge vs. Skylake: My observations and opinions on the subject

[Marinatall_Ironside]

Greetings,

 

Skylake has been lighting up like crazy, even I'm excited on the brand new microarchitecture Intel has to offer. But should you upgrade? Many have asked this question to others and themselves numerous times and the Internet as we know it, has answered those questions for all of you folks looking to move to a new platform.

 

The statements above are related to those who are on previous microarchitectures (Devil's Canyon, Haswell, Ivy Bridge, and Sandy Bridge) and the comparisons herein. Benchmarks has already been performed and there's a plethora of information, both valid and fabricated. But I will provide only valid ones to comply with the guidelines stated.

 

PC Perspective's test with discrete GPUs: http://www.pcper.com/reviews/Graphics-Cards/Skylake-vs-Sandy-Bridge-Discrete-GPU-Showdown

 

Their testing methodology is different, but confusing for an average reader at best. So I would advise to read how they did the tests to see how they stack up with Sandy Bridge before you make your decision. I didn't read the whole article, but what I could say is for single GPU performance at 1920x1080, Sandy Bridge held up surprisingly well for a four-year old microarchitecture. But when you add another GPU and run the cards in SLI/CrossFire, Skylake is clearly the winner the tests. But for most tests with a single GPU, it produced a 7-8% performance increase, which to me makes no difference at all in gaming performance.

 

It's not a completely comprehensive test, but the results are consistent enough that I think we can draw some very specific conclusions. First, there is absolutely a gaming performance difference between the Sandy Bridge Core i7-2600K and the Skylake Core i7-6700K. With just a single GPU, and a high end one at that, we saw measured average frame rate differences as well as frame time consistency differences at 1920x1080 in 3 out of 4 our test games. In the newest title of the bunch, Grand Theft Auto V, that gap was 25%! Other games ranged from 7-8%, which isn't enough to warrant a full platform upgrade on its own, but if you have been weighing your options for a while, this might be enough to tip the scales. -PC Perspective

For SLI though, that was far from the truth. The pair of GeForce GTX 980 cards running on the Core i7-6700K and Z170 motherboard produced a much better overall gaming experience, even at 2560x1440, than the older Sandy Bridge platform. Both average frame rates and frame times proved this to be the case: if you are a gamer considering or currently running on SLI, then you should really save some cash to make that next upgrade to Haswell or Skylake! -PC Perspective

 

So to summarize this from PC Perspective, for those of you who are on their Sandy Bridge systems, be it mainstream or top-of-the-line at the time, just hold on to it for another year or so. But if you plan on or are currently running a multi-GPU setup, then Skylake looks like a compelling upgrade. But if you're building your first Intel system, then definitely go for Skylake.

 

Now to Tom's Hardware's review of the Skylake SKUs: http://www.tomshardware.com/faq/id-2752766/skylake-upgrade.html

 

They list and describe all the new bells and whistles for the Skylake SKUs, such as DDR4 nad DDR3L support, Z170 motherboards to go with it, and the CPUs themselves. But what I'm more interested in is should you upgrade? That's what I'm getting at here with this article, or so to say. But what they say for Haswell/Devil's Canyon users is to wait another year or so, while on the other hand for Sandy Bridge and Ivy Bridge users is to go and upgrade as it offers a 30-45% increase in performance, but where exactly will users see an increase in performance? Gaming? Productivity? IPCs? So here are the quotes below here from Tom's Hardware:

For haswell users, it's a no in general. The key advantage of Skylake is feature set, not performance. So if your looking for a good boost in speed then don't switch to Skylake, rather switch to Haswell-E which is a massive boost in performance to Haswell and Skylake.

Another good reason to not upgrade is overclocking. Your i5 K sku or i7 K sku overclocked at 4.5Ghz or beyond is actually a little bit faster than the 6600K or 6700K at stock speeds. While you could upgrade and overclock, would a 10% increase in performance be worth $500 of parts?

Now, if your the select few that uses lots of usb C and USB 3.1 devices, plus you need high speed storage from twin M.2 slots then upgrading makes perfect sense. -Tom's Hardware

This time it's a yes. Sandy Bridge and Ivy bridge are both getting pretty old by now, and upgrading to Skylake will yeld a 30-45% (45% if your a sandy user) increase in performance. You will also get the latest technologies from Skylake, namely power efficiency, a variety of USB ports, high speed LAN, and probably the biggest upgrade will be high speed storage. Together, all these features makes it a worthy upgrade to Skylake. -Tom's Hardware

 

To summarize what Tom's Hardware has to say about it, to me it's a little polarizing when you look at both PC Perspective's article and Tom's Hardware's article side-by-side. But my stance will remain is to just stick it out for another year if you only do single GPU, but upgrade if you do Multi-GPU setups and/or you want to get the latest features that fits you well.

 

From my point of view, if you were me, if you can wait, wait for AMD's Zen microarchitecture because they may bring much needed competition. If AMD just rips, then I would be floored because it has been both Intel as the go-to for performance and it has been that incremental 6-8% performance increase for four freaking years now, which, as a PC enthusiast, makes me want to hold on to my system for longer, even the top-of-the-line one for longer until something with a large performance increase like what happened with Nehalem when it was replaced by Sandy Bridge.

 

Now to conclude this. Is it worth it to upgrade from your previous system to Skylake? I guess it's up to you to decide. Should you go to Skylake for your first system? Definitely go for it. But I would take my recommendation for you folks who are on their previous generation systems right now to wait another year or so. But ultimately you decide what's right for you.

 

Also if you're interested, please read my blog entry below. The subject I have documented can really bring much-needed discussion to the table..

 

My blog entry: The PC Hardware Debate (From My Point of View)

[Agent181]

Not upgrading until zen but it better be good otherwise it's a 5820k for me

[kpreg]

This is a really good analysis, thank you! I'll probably be holding off until Zen too.

[SurvivorNVL]

Probably gonna run Skylake, and then Skylake-E in a year or Zen.  Depends whichever is better.  

[deviant88]

Until we get 6 core i5 for mainstream desktop at 200-250$ i couldnt care less about any skylake or other childish marketing nonesense made by intel.

Skylake is only relevant if you upgrade from any AMD cpu or Q series or 1st gen i5/i7 nehalems i think.

[El_indian]

Ryan mention in vid: "As you increase resolution, the impact your CPU has tends to be less".

 

But why?

[patrickjp93]

Not upgrading until zen but it better be good otherwise it's a 5820k for me

At that point the 6820K/7820K will be out.

[patrickjp93]

Ryan mention in vid: "As you increase resolution, the impact your CPU has tends to be less".

But why?

Because the bottleneck then turns out to be your GPU. You only need the CPU to be issuing draw calls and sending/receiving info from the GPU(s). If the GPU(s) can't keep pace, then improving the CPU performance is pointless.

[ACatWithThumbs]

There is no need to upgrade unless you use a program that does extreme heavy CPU tasks.
Gaming is for sure not one of them buying an SSD or GPU will do waaay more to your performance than a CPU especially with DX12.
And the consoles with their 1,6ghz/1,74ghz AMD APUs will for sure not bring any CPU heavy games the Ps4 can't even keep up with the CELL processor of the Ps3.
Even most professional programs are far faster on CUDA or OpenCL so even there CPU performance is getting irrelevant for many professionals.

If they release an 8 core i5 I would still not upgrade because I simply have no reason to.
 

[tomas710]

 

I totally agree, and we have seen AMD stock drop a lot, but overall Intel hasn't been doing well. This lack of competetiveness is taking down the market of PC enthusiasts, and what some people don't realize is, without AMD having a breakthrough, Intel will not improve, and it will become more and more likely they'll stop investing in research for high end CPUs and move that money into power efficiency for mobile devices. That's why i hate fan boys, cause they are basically tearing the PC community apart. Imagine what would intel do if the sandy bridge owners upgraded to zen, they would shit their pants and release a truly enthusiast CPU, maybe a 6 core at the 4 core price point. But we gotta be objective when it comes to product quality, and AMD better fucking deliver, not for them, no for their fanboys, for everyone.

[bomerr]

There isn't any point in holding off to upgrade as kaby lake will be a skylake refresh. 

 

IMO 5820k is the go to CPU right now for an upgrade or high-end build. 

 

6600k is worth considering for a mid-range build. 

 

 

Until we get 6 core i5 for mainstream desktop at 200-250$ i couldnt care less about any skylake or other childish marketing nonesense made by intel.

Skylake is only relevant if you upgrade from any AMD cpu or Q series or 1st gen i5/i7 nehalems i think.

 

I would say that is true for most people however if you run dolphin emulator than upgrading to an AVX 2.0 haswell+ system makes sense. 

 

 

I totally agree, and we have seen AMD stock drop a lot, but overall Intel hasn't been doing well. This lack of competetiveness is taking down the market of PC enthusiasts, and what some people don't realize is, without AMD having a breakthrough, Intel will not improve, and it will become more and more likely they'll stop investing in research for high end CPUs and move that money into power efficiency for mobile devices. That's why i hate fan boys, cause they are basically tearing the PC community apart. Imagine what would intel do if the sandy bridge owners upgraded to zen, they would shit their pants and release a truly enthusiast CPU, maybe a 6 core at the 4 core price point. But we gotta be objective when it comes to product quality, and AMD better fucking deliver, not for them, no for their fanboys, for everyone.

Moore's law is ending or over. 

 

Intel is going to want to milk as much money as they can in the next 5-10 yrs before performance really slows down. You think the year over year IPC improvement right now is bad, wait until 2025. So I can't exactly blame them for what they are doing. 

[Sovek]

There is no need to upgrade unless you use a program that does extreme heavy CPU tasks.

Gaming is for sure not one of them

Wrong, I know a few games, namely RTS titles that are heavily CPU intensive. I cant even get Planetary Annihilation to run smoothly on my i3. Kerbal Space program is another CPU heavy game that could probably benefit more from skylake.

[FellTheSky]

Its worth the upgrade if you are on a locked cpu like core i5 2400/3330, but if you are on the legendary 2500k/2600k there is no reason to upgrade. I leaved a comment on the video part of that article debating that it was miss leading to the consumer to say: "hey SB is thrash now, go buy skylake", and the only answer i got from them was "intel didnt pay us to make this", funny enough saying nothing about my arguments.

If you are a upgrade junkie, you probably already upgraded, but if you are on 2500/2600/3770/3570 K's, you have no reason to upgrade

[slay english]

Its worth the upgrade if you are on a locked cpu like core i5 2400/3330, but if you are on the legendary 2500k/2600k there is no reason to upgrade. I leaved a comment on the video part of that article debating that it was miss leading to the consumer to say: "hey SB is thrash now, go buy skylake", and the only answer i got from them was "intel didnt pay us to make this", funny enough saying nothing about my arguments.

If you are a upgrade junkie, you probably already upgraded, but if you are on 2500/2600/3770/3570 K's, you have no reason to upgrade

My 2700k isn't legendary

[El_indian]

Because the bottleneck then turns out to be your GPU. You only need the CPU to be issuing draw calls and sending/receiving info from the GPU(s). If the GPU(s) can't keep pace, then improving the CPU performance is pointless.

 

So the CPU is the bottleneck at the lower resolution?

[bomerr]

So the CPU is the bottleneck at the lower resolution?

the more frames you render, the more the cpu becomes a bottleneck.

[El_indian]

the more frames you render, the more the cpu becomes a bottleneck.

 

Yeah that's why i'm confused as to why SB competes better with Skylake at the higher resolution...

 

Why is the SB chip seemingly doing less work at 1080p? 

[Sovek]

Yeah that's why i'm confused as to why SB competes better with Skylake at the higher resolution...

 

Why is the SB chip seemingly doing less work at 1080p?

It competes better at higher resolutions because at the higher res the GPU becomes the bottleneck. Higher res settings requires more work from the GPU because it needs to render more pixels, in some cases, twice as much

[Dabombinable]

For those going on about Zen, its IPC is predicted to be close to that of Haswell....

[El_indian]

It competes better at higher resolutions because at the higher res the GPU becomes the bottleneck. Higher res settings requires more work from the GPU because it needs to render more pixels, in some cases, twice as much

 

What extra work is Skylake doing at 1080p that the Sandy Bridge chip can't do that is creating the difference in performance (i'm referring to the PCPer benchamerks)?

 

And why isn't this performance difference maintained as we move up to 1440p?

 

I guess i need an eli5 here...

[Gotxiko]

I'll be upgrading to i5-6600k. Seems like a pretty good upgrade from my i5-2320. Of course, if you already have a 4th or 5th gen CPU, getting skyline is kinda pointless.

[Sovek]

What extra work is Skylake doing at 1080p that the Sandy Bridge chip can't do that is creating the difference in performance (i'm referring to the PCPer benchamerks)?

 

And why isn't this performance difference maintained as we move up to 1440p?

 

I guess i need an eli5 here...

I've never seen one where the SB beats a Skylake at 1080. a Skylake offers minimal performance increase in 1080p, but move up to 1440p and its practicly gone.

[bomerr]

What extra work is Skylake doing at 1080p that the Sandy Bridge chip can't do that is creating the difference in performance (i'm referring to the PCPer benchamerks)?

 

And why isn't this performance difference maintained as we move up to 1440p?

 

I guess i need an eli5 here...

Let's say @ 1080p fps is 90, @ 1440p it drops to 60 and @ 4k it's down to 30 fps.

 

Okay so at 1080p the cpu and gpu are both rendering 90 frames per second. Now why does the fps drop as the resolution increases? It's because the GPU can't put out as many frames. So the cpu no longer needs to render 90 frames, now it only needs to render 60 or 30 hence it's not under as high of a load.

 

To reiterate the cpu gets taxed with fps while the gpu gets taxed with pixels. 

[El_indian]

Let's say @ 1080p fps is 90, @ 1440p it drops to 60 and @ 4k it's down to 30 fps.

 

Okay so at 1080p the cpu and gpu are both rendering 90 frames per second. Now why does the fps drop as the resolution increases? It's because the GPU can't put out as many frames. So the cpu no longer needs to render 90 frames, now it only needs to render 60 or 30 hence it's not under as high of a load.

 

To reiterate the cpu gets taxed with fps while the gpu gets taxed with pixels. 

 

Hey that it makes sense to me now. Thanks! 

 

So the CPU doesn't need to do as much work at a higher res. Got it. 

[patrickjp93]

Yeah that's why i'm confused as to why SB competes better with Skylake at the higher resolution...

 

Why is the SB chip seemingly doing less work at 1080p? 

That is likely a driver issue. Either that or the tests were outliers.