3570k vs 2500k

aayjaay

Member
Jul 11, 2012
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I will be building a gaming PC is the next couple of months and I am still undecided between these two CPUs. I would be wanting to overclock to the low 4 to mid 4 ghz range in the future. I would be running this processor along side a HD 7850, 8GB RAM, and a ~600w PSU. Also, price is not an issue in picking between these two CPUs as they are only ~£10 apart.

I have gathered that the 2500k has a better overclock potential and generally runs cooler and the 3570k has better IPC and is better clock-for-clock compared to the 2500k. I have also read that it is more future proof (e.g. it is compatible with PCI-e 3.0) and generally has newer technology.

Here are my questions:

1) What kind of temperatures would I be expecting if I overclocked to 4 - 4.5ghz with a 3570k compared to a 2500k? If I was going for an overclock like this, what kind of cooling would I need?

2) How much faster is the 3570k compared to the 2500k clock-for-clock? I've heard all sorts of numbers from 100mhz to 400mhz faster. Also, does this difference really matter? Would I see an increase in performance in gaming? Also, what kind of an fps boost would overclocks like these give me. Is there a significant increase in say, a ~1ghz overclock? I've heard that most of today's games are GPU bound and that these processors at stock speeds are overkill for most games anyway?

3) Basically, which one's better? :p

If it matters, I will be wanting to play games like BF3 (and other generally graphically demanding games) on max settings with 1920x1080.

As you can tell, I'm a bit of a noob when it comes to building PCs so all help is appreciated, thanks :awe:
 
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ShintaiDK

Lifer
Apr 22, 2012
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3570K is around 5% faster clock for clock. And if you ask if it matters. Why are you overclocking?

Get a 3570K, it also uses 20% less power and got a much better iGPU.

And your 7850 is the main bottleneck in terms of FPS.

Nobody can really tell you about overclocking performance before its tried. All chips are different.

You can get a 2500K that can barely cross 4Ghz. And you could get a 3570K that can do 5Ghz or vice versa.
 
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Smoblikat

Diamond Member
Nov 19, 2011
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the 3570K is about 5% better than a 2500K, hardly worth the price difference. I think most IB's stop at 4.5ghz, while SB generally does 4.8 (mine does 5.4)
 

pantsaregood

Senior member
Feb 13, 2011
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The i5-2500K and i5-3570K will both reach around 4.5 GHz relatively easily. The i5-3570K will have somewhat higher core temperatures, but they should still be manageable.

Difference in per-clock performance is negligble. At its heart, Ivy Bridge is a die shrink of Sandy Bridge.

As for "future proof" with PCI-E 3.0 support and such - it isn't even worth mentioning. Modern multi-GPU cards can function at or near full speed in PCI-E 2.0 4x slots - that's the same speed as an AGP 8x slot, a standard that was phased out back in 2004. The extra bandwidth of PCI-E 3.0 is meaningless when you have nothing to saturate it with.

Personally, I'd get the 3570K. It will overclock just as well and it is a lot more power efficient. It may actually overclock a bit further - people just seem afraid to push it because they perceive it as running "hot." Ivy Bridge has a maximum safe operating temperature of 105 C - even with some serious overvolting, you won't easily hit that.

EDIT: Most Sandy Bridge CPUs most certainly do not hit 4.8 GHz on any sort of "safe" voltage. If yours really hits 5.4 GHz, you have a real gem. Ivy Bridge doesn't really "top out" any sooner than Sandy Bridge does, the cores just run hotter. If you want to be really technical, the 3570K has around a 3% higher clock speed than the 2500K, as well as some extremely minor core improvements that lead to 0-6% performance gain for Ivy Bridge. Optimally, you may see a 3570K outperforming a 2500K by around 9%.
 
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aayjaay

Member
Jul 11, 2012
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Since the IB runs hotter, to reach the low-mid 4ghz (4.x - 4.5) range, would I need a better cooler for the 3570k than the 2500k or are the temp differences between the two CPUs not high enough to use a better cooler? Generally speaking, what are the temps of a 3570k compared to those of a 2500k?

Also, about the 9% gain on performance that you mentioned for the IB over the SB, is that 9% increase a pure clock speed increase or is it a 3% clock speed increase + other factors? What kind of a mhz increase would these percentages translate into?
 
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Smoblikat

Diamond Member
Nov 19, 2011
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Since the IB runs hotter, to reach the low-mid 4ghz (4.x - 4.5) range, would you need a better cooler for the 3570k than the 2500k or are the temp differences between the two CPUs not high enough to use a better cooler?

Also, about the 9% gain on performance that you mentioned for the IB over the SB, is that 9% increase a pure clock speed increase or is it a 3% clock speed increase + other factors?

I always thought 3570 vs 2500 was taht 2570 had a 5% performance gain CfC. At 4.5 the same cooler should be fine for both, the difference is that the IB wont go much higher while the SB will have plenty of OC headroom.
 

aayjaay

Member
Jul 11, 2012
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At 4.5 the same cooler should be fine for both, the difference is that the IB wont go much higher while the SB will have plenty of OC headroom.

I'm not going to be going for crazy overclocks anyway. I'd be satisfied with 4.5. Also, sorry for repeating myself, but with the same cooler on both, what would the temp difference be between the two CPUs?
 

pantsaregood

Senior member
Feb 13, 2011
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Ivy Bridge will run hotter, period. It is designed to tolerate higher temperatures. Sandy Bridge hardly has "plenty of headroom" above 4.5 GHz, either. After around 4.5 GHz, voltage increases provide minimal clock speed returns on most chips. Sandy Bridge running above 4.6 or 4.7 GHz without obscene voltage is extremely rare. Ivy Bridge may or may not manage higher without extreme voltage.

Again, stop with the "IB is too hot to OC" nonsense. Ivy Bridge cores do run hotter than Sandy Bridge cores, but the package itself produces less waste heat. My 2500K barely idles above room temperature, and at load it hits around 55C at 1.37v. If an Ivy Bridge CPU runs at 85C under full load, who cares? It is entirely within safe thermal spec.
 

Yuriman

Diamond Member
Jun 25, 2004
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Results from my Ivy chip:

4.3Ghz:
Stable at 1.144v
75c Linpack loaded (hottest core)
66c Prime loaded
Draws approximately 80w

4.4Ghz:
Stable at 1.200v
81c Linpack loaded
75c Prime loaded
Draws approximately 92w

4.5Ghz:
Stable at 1.256v
90c Linpack loaded
82c Prime loaded
Draws approximately 104w


Ivy draws considerably less power than Sandy. It overclocks higher on a given voltage as well as drawing less power at a given voltage/clock. Ivy runs a lot hotter than Sandy due at least in part to it having a smaller die. Linpack (IBT/LinX) is an unrealistic load and you're unlikely to ever see temperatures that high in the real world, but because Ivy runs hotter you're going to be capped at 4.5-4.7Ghz without unusual cooling if you want to prevent thermal throttling in the most extreme loads.

For reference, Intel recommends staying under 1.5v on these chips, but you become thermally limited loooong before hitting that.

On a Sandy, you can crank up the voltage and clock it to the moon.
 

MustangSVT

Lifer
Oct 7, 2000
11,554
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For me, Ivy is a much greater risk. Because if I get Ivy..... I will have to remove the die cover.
 

Arkaign

Lifer
Oct 27, 2006
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It's essentially a meaningless metric between the two if you're an overclocker who uses a discrete GPU. The differences will be miniscule at best.

If you're running IGP (who does with a K CPU, lol), or running stock speeds (Again, WHY with a K series CPU!?!?), then the Ivy will be a little better. The IGP still sucks, but less so to some degree.
 

bl00tdi

Member
May 31, 2012
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If you were a maximum overclocker with appropriately powerful cooling I would strongly recommend SB. The maximum 2500k overclocks can overcome the IPC disadvantage if you're willing to push it. For mild 4.0-4.6 overclocks the 3570k is the better option. Or neither and wait for a revised IB stepping..

Sent from my SCH-I510 using Tapatalk 2
 

2is

Diamond Member
Apr 8, 2012
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You can get a 2500K that can barely cross 4Ghz. And you could get a 3570K that can do 5Ghz or vice versa.

Sure... It COULD happen, but it's about as unlikely as me passing out before submitting this reply, so if you read it... Well, yeah... That's how unlikely it is.

While I do agree that the 3570 is the way to go, I also think there is plenty of data out there to give ball park figures. Are the gauranteed? No, but they're certainly going to be more helpful to the OP than made up figures that are unlikely to happen.
 

pantsaregood

Senior member
Feb 13, 2011
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Would just like to say your 90C load under IBT is perfectly fine. You may have gotten the short straw on the overclockability of your specific chip, though. Looks like you started getting diminishing returns around 1.2v.

A "maximum overclocker" would almost certainly prefer Ivy Bridge. Extreme overclockers are hitting 6 GHz on Ivy Bridge pretty regularly. Hitting 6 GHz on Sandy Bridge requires a 5 MHz BCLK increase - a large portion of SBs can't take that. This is the same ridiculous take people had on Prescott: "it doesn't overclock well because it runs hot." It may run hot, but it also overclocks very well.
 

AtenRa

Lifer
Feb 2, 2009
14,003
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Get the 3570K, OC to 4GHz (default vcore) and you should be fine for every game. HD7850 will be the limiting factor most of the times.
 

Arkaign

Lifer
Oct 27, 2006
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6ghz is basically a suicide-run, even under extreme cooling, for any amount of use. For all practical purposes with good air cooling or even water, there's no real difference once overclocked to common limits to either in terms of enthusiast performance (using discrete GPU, overclocked to max stable without insane volts). There's nothing wrong with going IB at all, but it's hardly different in the big picture. Best/worst case each way after all is said and done might be 1-2% one way or the other.
 

lopri

Elite Member
Jul 27, 2002
13,314
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3570K runs hotter than 2500K because of PCI-E 3.0, I suppose?
 

Yuriman

Diamond Member
Jun 25, 2004
5,530
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3570K runs hotter than 2500K because of PCI-E 3.0, I suppose?

No, because of 22nm vs 32nm. The Ivy has a higher ratio of heat output to surface area because it's a significantly smaller die, even though it does produce less heat.
 

jacktesterson

Diamond Member
Sep 28, 2001
5,493
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get a 2500k

Easier to cool and cheaper. You will see no difference. PCI 3.0 vs 2.0 is basically pointless right now, Video cards still can still run near 100% on PCI 2.0 x4, yet alone x16.

I'd only recommend the 3570k over it right now if you want to use the HD 4000


Both will be just fine.
 
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pantsaregood

Senior member
Feb 13, 2011
993
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Stop saying "easier to cool." Ivy Bridge runs hotter than Sandy Bridge, and it is perfectly okay for it to run hotter! Just because your 2500K runs at 60C full load doesn't mean that a 3570K needs to do the same to run at a "safe" temperature.
 

vazz

Junior Member
Jul 12, 2012
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If you are choosing for a new build, I would marginally recommend 3570K but only because it consumes marginally less power and because it is the current generation. 3570K is a straight replacement for the 2500K but in reality, hardly better if at all.
 

imagoon

Diamond Member
Feb 19, 2003
5,199
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It's essentially a meaningless metric between the two if you're an overclocker who uses a discrete GPU. The differences will be miniscule at best.

If you're running IGP (who does with a K CPU, lol), or running stock speeds (Again, WHY with a K series CPU!?!?), then the Ivy will be a little better. The IGP still sucks, but less so to some degree.

Overclocked ESXi box using internal IGP here. Pointless to put a dedicated card in that box.
 

rickon66

Golden Member
Oct 11, 1999
1,824
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I don't understand why anyone would buy SB at this point, bragging rights over an overclocking number? IB is the newest technology and superior in all practical anf tangable ways. Just get an IB, put a mild overclock on it and enjoy.
 

BonzaiDuck

Lifer
Jun 30, 2004
16,689
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I don't understand why anyone would buy SB at this point, bragging rights over an overclocking number? IB is the newest technology and superior in all practical anf tangable ways. Just get an IB, put a mild overclock on it and enjoy.

After weeks of casual web-search "research," I agree. Maybe the analog to this decision is whether to upgrade a P67 mobo to Z68 versus simply jumping to the Z68 -- a dilemma that was discussed last year. If you have a Sandy -- no need to upgrade; if you don't, go with the Ivy. Otherwise, the analog pursued further should probably fall on its face . . .

I also looked into "cooling preferences." Some people have opted for the Corsair "H100" or similar "canned" water-cooling kits. Others are using everything from the CoolerMaster 212 or EVO to the Noctua NH-D14. These latter air-cooling solutions still seem as viable for the IB as for the SB CPUs.

You get an extra 5C of "headroom" on the Ivy Bridge TjMax for the Ivy -- probably for deliberate reason -- and as someone said: "Designed to handle slightly higher temperatures." So (I'm only guessing) -- you might find a decent over-clock setting and speed producing temperatures as much as 10C higher than would occur with a SAndy. And that's just a guess, but I'd bet on it . . . .
 

bl00tdi

Member
May 31, 2012
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A "maximum overclocker" would almost certainly prefer Ivy Bridge. Extreme overclockers are hitting 6 GHz on Ivy Bridge pretty regularly. Hitting 6 GHz on Sandy Bridge requires a 5 MHz BCLK increase - a large portion of SBs can't take that. This is the same ridiculous take people had on Prescott: "it doesn't overclock well because it runs hot." It may run hot, but it also overclocks very well.
Well if you're referring to sub-ambient for those OC's that's another story altogether. My admittedly ill-conceived "maximum overclocker" (as opposed to "extreme" ) term was describing anyone willing to push their particular CPU to the edge of stability on good ambient cooling. And by good I mean high end air or a custom loop. In my case, the "game" I run on my system is heavily CPU bound so I have typically overclocked my cpu's to the edge of stability WRT the cooling solution I had at the time and seen a tangible increase in frame rates the higher I went. It's possible that a higher overclocked SB could provide me with better overall performance regardless of newer technology/pcie 3.0/3D transistors/lower TDP etc. Those things are great, but all I want are higher FPS in a cpu-bound scenario in which I WILL Max out my overclock under water. That plus I can't really afford a 2011 build :(. If I really feel the need to have the latest and greatest, I can always wait for a revised IB stepping......or something.


To sum it up, just because it doesn't pertain to everyone doesn't make it an irrelevant consideration.
 
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