low consumption

[anikhtos]

there is e3-1220l cpu with tdp 20 watt but no graphics
there is i3-2100t cpu with tdp 35 watt with graphics
there is e3-1260l cpu with tdp 45 watt with graphics

e3-1220l 2c/4t
i3-2100t 2c/4t
e3-1260l 4c/8t

an 6450 ati card will be around 25 watt max
so an e3-1220l +6450 ati goes to 20+25=45 watt

so which of the 3 cpu will make a lower power consumption system??
which will make the best overall system?!?!??!

 

[know of fence]

First Xeon looks good and can turbo to 3.4GHz. 4 cores simply can't be all that efficient.

But how do you even buy a Xeon processor?

 

[Magic Carpet]

Stick with i3, i.e. the golden middle ;-p

 

[Concillian]

i3 2100 in an Intel branded board (fewer misc garbage running, so total system power is lower)

 

[paperwastage]

First Xeon looks good and can turbo to 3.4GHz. 4 cores simply can't be all that efficient.

But how do you even buy a Xeon processor?

newegg has some xeons

otherwise, you have to search or find a retailer

https://www.google.com/search?q=+e3-1220l+&tbm=shop&hl=en&aq=f

http://www.memory4less.com/m4l_itemd...-001&rid=fd_10

 

[Maximilian]

I did a bit of looking into that the other day, low power consumption CPUs. The demand for them is extremely low so they are expensive and difficult to find.

Plus i think that if you took a 2600 non K and downclocked/downvolted it to the same speeds as that E3 1260L you would effectively have the same chip power consumption wise. It would be interesting if someone did some testing with regards to that, 95w CPU downclocked to the speed of the 45w chip and undervolted as far as it can go VS 45w CPU @ stock.

 

[anikhtos]

not that difficult to find a low consumption processor. I live in europe so i have found a half of dozen german shops that sell 1220l and 1260l (more shops sell the 1260l)
1260l sold for around 270 euro
1220l sold for around 170 euro
i3 2100t sold for around 120 euro
i5 2500k sold for around 200 euro
17 2600k sold for around 280 euro
so actually 1260l is cheaper to get than a 2600k?
in many reviews intel claim that the L chips are hand picked cheery chips with exceptional good electrical characteristics. so i wonder can you really get 45 watt with an 2600k or 2500k undervolting underclocking it to the levels of an 1260l??? is there any owner of a 2500k or 2600k over here that has the time to undervolt underclock and tells us how much watt the cpu drain ?!??!
by the way i3 2100t is in the supported list of the c chips to support ecc!?!?!? lol so you can built a system with a c202 c204 and c206 with an i3 and have ecc support.
well some emphasis to safety more than a few % of perfomance.

 

[Maximilian]

not that difficult to find a low consumption processor. I live in europe so i have found a half of dozen german shops that sell 1220l and 1260l (more shops sell the 1260l)
1260l sold for around 270 euro
1220l sold for around 170 euro
i3 2100t sold for around 120 euro
i5 2500k sold for around 200 euro
17 2600k sold for around 280 euro
so actually 1260l is cheaper to get than a 2600k?
in many reviews intel claim that the L chips are hand picked cheery chips with exceptional good electrical characteristics. so i wonder can you really get 45 watt with an 2600k or 2500k undervolting underclocking it to the levels of an 1260l??? is there any owner of a 2500k or 2600k over here that has the time to undervolt underclock and tells us how much watt the cpu drain ?!??!
by the way i3 2100t is in the supported list of the c chips to support ecc!?!?!? lol so you can built a system with a c202 c204 and c206 with an i3 and have ecc support.
well some emphasis to safety more than a few % of perfomance.

The 2600 is significantly cheaper than that 1260L, in fact i saw a 2600 on ebay for £150 yesterday, absolute steal. Why even consider the overclocking oriented 2600k for low power consumption setup? Non K chips can downclock/undervolt equally well.

Like i said before im betting that the "cherry picking" stuff is highly overrated, i don't think there would be a huge difference between a 2600 downclocked and undervolted to 1260L levels. The 1260L's may even be chips that failed to clock high enough to meet other xeon standards, the turbo on it for 4 cores is only 2.5ghz.

I doubt anyone here has a 1260L to test against although there is no shortage of 2600k owners. SPCR is likely to have 1260L owners who may be able to get direct from the wall power figured.

 

[anikhtos]

well with my system rig an athlon 250e a 45 watt cpu
with air cooling
i get 24 celsius idle
and after 10 minutes running prime95 i get 32celsius per core or cpu temp 34 celsius as stated from cpuid hardware monitor software.

so having a cpu at this low temps is important to me.
what is the max temp this cpu can handle i am thinking of disconecting the fan and see what the max temp will be then any suggestions?!?!??!

i was thinking to take an athlon615e as an upgrade but then i said why not a mobo and a sandy bridge.

 

[Zap]

Plus i think that if you took a 2600 non K and downclocked/downvolted it to the same speeds as that E3 1260L you would effectively have the same chip power consumption wise. It would be interesting if someone did some testing with regards to that, 95w CPU downclocked to the speed of the 45w chip and undervolted as far as it can go VS 45w CPU @ stock.

SPCR tested different TDP versions of the "same" model CPUs.
Core i3-2100 65W
Core i3-2100T 35W
Core i5-2400 95W
Core i5-2400S 65W
Link to SPCR review

During benchmarking, I think they found that the normal Core i3 used only around 5W more. However, it finished tasks faster than the lower clocked low wattage version, thus the overall electricity used for the duration of the test was less than the low wattage version.

 

[Maximilian]

SPCR tested different TDP versions of the "same" model CPUs.
Core i3-2100 65W
Core i3-2100T 35W
Core i5-2400 95W
Core i5-2400S 65W
Link to SPCR review

During benchmarking, I think they found that the normal Core i3 used only around 5W more. However, it finished tasks faster than the lower clocked low wattage version, thus the overall electricity used for the duration of the test was less than the low wattage version.

Ah awesome, just what i wanted to see. From their conclusion about the normal i5 and low power i5:

"Still, the power consumption difference is slim enough that an i5-2400 with a small undervolt will deliver similar results without sacrificing any speed. This has been our biggest criticism of these specialty low power processors — you can create your own with simple undervolting on a decent motherboard."

So best off buying a "normal" cheaper CPU and undervolting it, the extra performance is there later if needed which isnt the case with the "low power" varients.

 

[jpiniero]

I'd be surprised if OEM mobos supported changing the voltage though.

Also keep in mind that since Intel went to groups of TDPs, the "real" TDP can be much lower than stated. I don't think the S and T models are golden samples either.

 

[Zap]

So best off buying a "normal" cheaper CPU and undervolting it

Right, or leaving it at stock speeds. Their testing was at "50% heavy load." At idle the CPUs draw around the same, with the low wattage versions having the most power savings under load versus the normal CPUs. If your system sits idle for long periods of time (leave it online for downloading?) or you are mostly just doing light tasks (web browsing, email, instant messaging, video chat, watching movies or web videos, office work, photo work) then you are probably spending most of your time idling or close to it.

 

[know of fence]

is there any owner of a 2500k or 2600k over here that has the time to undervolt underclock and tells us how much watt the cpu drain ?!??!

Clarkdale/Nehalem + Sandy Bridge CPUs do underclock+undevolt themselves constantly by changing the multiplier and Vcore, e.g. a bottom-end Clarkdale core i3 530 goes from

9 multi x 133.7 MHz @ ~0.900 V Vcore --> 1.2 GHz
to
22 multi x 133.7 MHz @ ~1.100 V Vcore --> 2.9 GHz

That's how it's possible to get <40 Watt from the wall in idle with a 78W TDP rated APU. There isn't really a point of pushing the clocks lower, while voltage can AFAIK only be set upwards of Intel's Voltage IDentification values, which adjust themselves depending on load and temperature. With lower multipliers on Xeon chips it may be possible to push voltage down to 0.250 Volts as well as up to 1.520 V (page 74
http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-1-datasheet.html )

The 1220 Xeon 20W L-version does cost the same as it's 80W higher clocked analog, which suggests that they are the same sample chip with similar electrical qualities, just different pre-set maximum multipliers.

 

[Ben90]

so having a cpu at this low temps is important to me.

Why?

 

[Zap]

Why?

I'm curious too. Maybe for passive cooling? IDK. However, just having low temperatures doesn't really do anything useful for stock speeds and normal (even quiet) cooling.

 

[skipsneeky2]

My i3 2100 on a h67 motherboard using my 6790 i pull these numbers according to coretemp...

0.9807v or around 5.8 watts idle clockspeed=1.596.37mhz
1.1809v or around 28.6watts load clockspeed= 3.092.96mhz

 

[anikhtos]

I'm curious too. Maybe for passive cooling? IDK. However, just having low temperatures doesn't really do anything useful for stock speeds and normal (even quiet) cooling.

yeap for passive cooling.
well i get now max 35 celsius for the cpu running prime95 so i imagine if i find a good heatsink i could passive cool it

 

[Ben90]

Just be careful with how you compare temperatures. No CPU today in the power envelopes we are talking about will run the cores at 35*C load. Especially not the Athlon 250e.

Intel and AMD measure temperatures at different points in the chip. If you are not overclocking, Sandy Bridge temps are safe up until around 98*C 24/7. Basically don't worry about temperatures unless it is throttling.

 

[Zap]

yeap for passive cooling.
well i get now max 35 celsius for the cpu running prime95 so i imagine if i find a good heatsink i could passive cool it

You don't need super low temperatures to passively cool, and "passive" is somewhat of a misnomer with computers because you still need airflow. BITD I was "passively" cooling dual core CPUs such as socket 939 Athlon 64 x2, and socket 775 Core 2 Duos. Not only that, but overclocked as well.

Sandy Bridge temps are safe up until around 98*C 24/7. Basically don't worry about temperatures unless it is throttling.

Yeah, most people obsess about temperatures for little reason, just because in the past or with some other chips temperatures were sometimes a huge issue with overclocking. With Sandy Bridge, temperatures are about as non-issue as it can be.

 

[Concillian]

yeap for passive cooling.
well i get now max 35 celsius for the cpu running prime95 so i imagine if i find a good heatsink i could passive cool it

Low temperature and low consumption are two different things.

Passive cooling is also something that you don't want to do unless you have a VERY special need.

Unless you're spending $200+ on your case, and it has heatpipes and such coupling your CPU to the case itself, you need a fan somewhere. May as well make that somewhere right next to whatever part needs cooling the most (CPU or GPU or both). Exceptionally quiet fans are easier than ever to find. Like, so quiet you can't hear them unless your ear is right next to them.