Core i7-2720QM or Core i5-560M which one will produce more heat.

Hi,

I have Dell XPS 15 L501X with Core i5-560M.

I ordered L502X Core i7-2720QM and planning to return L501X.

But if the L502X Core i7-2720QM produces more heat then i will cancel the order.

Please advise.

 

Clearly the quad core i7 will produce substantially more heat especially under load. To be more specific, the i7-2720QM is rated at 45 watts vs the 35 watts of the i5-560M. I have the i5-460M with my L501x and watching HD videos already makes the left side slightly warm. Playing games like SC2 becomes much warmer. I can only imagine how uncomfortably warm it will become when using the 2720QM.

 

I thought heat depends on Lithography:

Since the i7 740 had Lithography 45 nm
and i7-2720QM has Lithography 32 nm

And what is TJUNCTION.

Please fill me in with complete knowledge.

 

While several factors come into play when determining heat emissions, I would imagine that the number of transistors would be the most prominent factor given all else equal. Comparing the ~5.59 million transistors used in the Nehalem i5s to the ~1 billion used in the i7-2720QM, I would imagine heat levels would be substantially higher. Perhaps there is a computer engineer on this board who can further elaborate on this inquiry?

 

More cores do not equal higher heat emission when executing the same task, in fact, the sandy bridge is more efficient.
What does this mean? When executing the same moderately heavy task, in the end the i5-560m will emit more heat under load.

Idle is an completely diferent story, but i heard the sandy bridge quadcores have more efficient power gating features than the previous generation.

 

So exactly through what mechanism does the Sandy Bridge series manage to achieve more efficiency in terms of heat emission?

 

More cores don't, but a higher TDP does, and the i7 SB still has higher TDP than i5 duals.

 

If i knew, i wouldn't be here

If sandy bridge is twice as fast and emits twice as much heat at full speed, does it matter in the end? Not at all.
It simply doesn't matter if you use 50watts of power in 10 seconds, of 500 watts of power during 1 second. The heat emmissions are the same.

 

The i7-2720QM will be hotter under a full load than the i5-560M.

Take a look at the TDP- 45 Watts vs 35 Watts, both numbers chosen by the same manufacturer, Intel. The TDP isn't the maximum wattage of the processor, but rather the amount of heat that Intel recommends that the cooling system can dissipate.

As far as idle temperatures and "light loads" like web browsing go, I don't know (but I'd bet the Quad runs hotter). Also, the same "full load" on the dual-core processor isn't going to be a full load on the quad-core processor, so it's tricky. You'll probably have to find a review site that includes temperatures.

And TJunction is the maximum temperature the processor can handle before it Throttles (lowers performance to cool down), although Dell can and will make this number lower.

 

In fact the Tjunction refers to the maximum temperature before the system shuts down and had noting to do whit the temperature it stats throttling.

 

Hmmm. I remember reading that these i series mobile processors won't power off til 120C+, but in theory it should never get that hot unless the heatsink isn't attached. I'll see what I can find.

 

Like someone else said though, Dell gets to pick the final number in the BIOS.
Hence all the problems those poor early SXPS 16 owners had to deal with.

 

CPU TDP isn't the only thing that affects heat, also the way the cooling system is designed, how the cheapo thermal paste was applied.

 

Just curious, but yeah, a quad core will produce a little more heat, but what's the worry? with the internal cooling fans, and I am guessing here, a 9 cell battery will probably be necessary for the power consumption, which will lead to better ventilation, and even if that wasn't enough, there are cooling mats available. Why make a decision solely based on CPU heat?

The Best Nvidia driver 435M/445M

 

What do consider uncomfortably warm? I play SC2 and all 4 cores of my i740QM never exceed 75-79C? all within the norms. Above 90C yeah, I would be concerned but those numbers I posted are from 3-4 hour sessions, albeit just campaign because I SUCk! but still...

 

I earlier got Dell xps 15 with i7-740qm. Used the Antec 200 cooler. That didn't help.
No doubt it cooled my laptops bottom, but the keyboard and left palmrest were quite warm near to hot.

That made me return the computer.

No we have sandy bridge i7. Dont know how it is.

Looks like we have to choose between power or heat.

 

Well, Dell is known for their crappy thermal pasting job ,and the left palmreast is the location for the GPU, also known for crappy thermal pasting. If your smart with how and where you place you lappy, go for power, the heat difference won't be that much for the Sandy Bridge.

 

When talking about the l701x like Rooster said we have not seen temps above 80 degrees and definitely have never experienced any throttling.

You returned your XPS1,5 so what temps were you getting on that? and what temps are you expecting?

You say your left side was very warm/hot which to me sounds like you were unfortunate and got a duff laptop as I know a few others have had and got replacements but don't start to think this is the norm because it definitely isn't and whether you get an i5 or i7 it shouldn't make that much difference.

 

On med settings at 1080p for SC2, my cpu never exceeds 65 degrees.

 

You guys who post low temps are lucky if you're at a place where ambient temps are like 18-22C. Over here the ambient temps are higher, maybe 26-30C.

Anyways, the old quads were really hot all the time - which can be felt if you're not in snowy/breezy/cold surroundings, whether idle/browsing or gaming. Yes, it depends on the laptop's cooling system (e.g. an XPS M1330 with Intel GPU and Pentium T Series CPU is hot, or a small netbook, or an old Dell Latitude with archaic Pentium M CPU and Intel GME), but ultimately a hot CPU is a hot CPU.

Why decide based on CPU temps? Easy. In many situations dual cores are enough (and can even overcome) quad cores. Of course the new SB quads will be better in terms of performance, but they are still hotter. I would go for the i7 dual core if available, because it means much more battery life and much less heat (any i7 quad user would know).

 

Get a Sandy Bridge dual-core if heat is a real concern.

 

You're lucky, I have never seen less than 51/52C idle here with a quad core i7, and I always thought people in America/Europe had 40+C idle temps only because it was colder (but it is during certain times). But I suppose the 17 inch would be different compared to a smaller XPS 15 or SXPS 16.

 

I saw this and wanted to post my temps. However, Please note that I removed the stock thermal paste and used arctic silver 5.

Idle: 47-51c after usage, not before.

moderately intense usage: 80-84c.

extreme usage: 84-88c.

The AS5 has not passed the break-in stage so I expect the temps to drop a few more degrees.

System: DELL I7 L502x

 

Which i7 processor are you running?

 

sorry lol 2720qm