Official Sandy Bridge / LGA1155 for HTPCs Thread - Page 50

Same here. I don't own a lab and certainly don't want to buy it and try. Beside CPU here, we got other components in the system. So 65W verus 95W I prefer to have more features and power over the 30W saving.

It depends on the difference in price and your tolerance for unlucky binning. TDP #s for a SKU are a guarantee, you might do a lot better (i.e. a 95W part that only draws 75W) but you won't do worse. When the premium is small, I do think it's worth it. As the gap widens, not so much.


TBH, the "green" part of the TDP question isn't as compelling to me as the HSF + active cooling. I place a premium on a quiet, good looking HTPC; something that is much easier with at 65 (or 35)W CPU.

What's Pentium?

This is a low-end family of the Intel Sandy Bridge processor ("Celeron" Sandy Bridge will also come soon) including G620T, G620, G840 and soon G850, all 2 core, 2 thread processors with integrated graphics called "Intel HD Graphics". Well, this is almost identical with "Intel HD Graphics" of the 1st gen Core i3 processor (Clarkdale). In particular it supports:

- HD audio bitstreaming
- AVC, VC-1, MPEG-2 and MVC (BR 3D codec) full hardware decode acceleration
- All video post-processing tasks of Intel Clear Video Technology implemented in the 1st gen Core i3.

Precisely speaking, MVC decode was not supported by the 1st gen Core i3, so this is new. The following new features added to the 2nd gen Core processor (i.e. Core i3/i5/i7 Sandy Bridge) are not supported:

- HDMI 1.4a 3D video format (Frame Packing)
- Quick Sync
- "Total Color Correction", "Skin Tone Correction", "Adaptive Contrast Enhancement" (personally I don't care much about these features).

If you are not interested in stereoscopic 3D with a HDMI 1.4a 3D display or Quick Sync, a Pentium processor, in particular G620 2.6GHz (fast enough for 2D HD video playback in non-DXVA and cheap), is an excellent choice.

As for stereoscopic 3D, Pentium supports the following 3D formats just fine:

- Checkerboard (supported by older Mitsubishi/Samsung 3D ready DLP displays, as well as the latest Samsung and LG 3D displays)
- Side by Side (Half)
- Top and Bottom
- Interleaved

as these formats are within HDMI 1.3 specifications.

T Version: 35W TDP

- Pentium G620: 2.6GHz, 65W
- Pentium G620T: 2.2GHz, 35W

So at first G620T seems to be a good choice for HTPC (lower power consumption -> lower noise, lower electric bill). Unfortunately this turned out not correct. AC power draw from the wall (measured with Kill-A-Watt) of the system consisting of

- Pentium (and Core i3) processor
- ASRock H61 mb
- 2 x 2GB DDR3-1333 (G6xx supports up to DDR3-1066, while G8xx supports up to DDR3-1333; not important for video playback, however)
- 1 x 3.5" HDD (WD20EARS)
- Enermax MODU82+ 525W PSU; not so efficient at lower power output despite "80 PLUS" (well, 80% efficiency is guaranteed at 20% = 105W DC output), but this doesn't matter to compare two processors.

	Pentium G620	Pentium G620 @2.2GHz	Pentium G620T
Idle	39W	39W	39W
BD playback by PDVD11 (DXVA)	43W	44W	43W
DVD playback by PDVD11 (TrueTheater HD)	47W	47W	47W
x264 HD Benchmark 2nd Pass	60W	56W	58W
Prime95	64W	58W	61W
FurMark	54W	54W	55W
Prim95+FurMark	76W	71W	71W

 

So basically G620T is not a cherry-picked die with lower leakage current, but just a lower-clocked version with lower running voltage. Even I can obtain a G620T from G620 by simply limiting the max multiplier to 22! A possible advantage of G620T is that it comes with a CPU cooler of height ~30mm (the same one as Core i3-2100T), that fits some SFF cases nicely (a disadvantage of this cooler is that it's pretty noisy at load; I would rather choose the normal G620 and this cooler if I need a good low-profile cooler, well worth the money). Otherwise I don't see a reason to choose G620T over G620.

I saw exactly the same relation between Core i3-2100 3.1GHz 65W and Core i3-2100T 2.5GHz 35W. Under the same configuration as above,

 

	Core i3-2100	Core i3-2100 @2.5GHz	Core i3-2100T
Idle	39W	39W	38W
BD playback by PDVD11 (DXVA)	44W	44W	43W
DVD playback by PDVD11 (TrueTheater HD)	56W	55W	56W
x264 HD Benchmark 2nd Pass	72W	63W	64W
Prime95	74W	64W	65W
FurMark	55W	55W	54W
Prime95+FurMark	88W	77W	72W

 

There is almost zero difference between the two at idle and video playback. I also tried to underclock 2100 by limiting the multiplier to 25. I got another 2100T instantly (except for Prime95+FurMark). Silent PC Review's article confirms this:

 

 

x264 HD Benchmark 2nd Pass

Processor	Frame/second	Power	Energy/frame
Pentium G620T	9.37 fps	60W	6.40 Joule/frame (= 60W/9.37fps)
Pentium G620	11.13 fps	58W	5.21 Joule/frame
Pentium G840	11.93 fps	64W	5.36 Joule/frame
Core i3-2100T	13.24 fps	64W	4.83 Joule/frame
Core i3-2100	16.30 fps	72W	4.42 Joule/frame

 

In general an "energy-efficient" processor consumes more energy to finish the task (of course nobody would choose an energy-efficient processor to do CPU intensive tasks).

BTW

- Athlon II X2 255: 9.71 fps
- Athlon II X3 450: 13.46 fps
- Phenom II X4 840: 20.51 fps

But these processors consumes much more energy.

Edited by renethx - 6/15/12 at 6:57am

How does AMD beat G620 + H61 for budget builds? Right now if someone came to me and said they want something to surf the 'net, watch HD videos, run Office and tasks like that I'd build nothing else. AMD was ALWAYS my go to for budget builds, even as soon as 6 months ago (exception: nettops and D525).

Llano better be something pretty amazing.

Renethx,

Any idea how well that low profile Gelid cooler would work with a 2100? If you have a Microcenter nearby it seems worthwhile to spend the $99 to get the 2100 over a 2100t or 620/620t. I'd just be worried about cooling, especially in a Habey like case.

Gelid is good enough for 2100. And you can always turn 2100 into 2100T easily (just set the max multiplier to 25).

Nice results, and good info, thanks for sharing all your tests. Just a side note, the 2100T does come with lower profile cooler, so while 2100 is cheaper, faster and could be moved into a 2100T kinda with the multi, people looking for low profile cooler still might find the 2100T a good solution.

A lot of people have noted that the 2100T cooler is kinda obnoxious however. So if you want a quieter cooler, you might want to save the $$$ up front and just invest in the better cooler.

A couple of low-profile coolers that are better than the 2100T/G620T stock cooler (30 mm tall) and shorter than the 2100/G620 stock cooler (46 mm tall). The cooling performance increases in this order (perhaps):

GELID Slim Silence i-Plus

Height: 28 mm
Fan: 75 x 15 mm, PWM, 1200 - 2600 rpm

Thermaltake SlimX3

Height: 36 mm
Fan: 80 x 15 mm, PWM, 1200 - 2400 rpm

SCYTHE Kozuti

Height: 40 mm
Fan: 80 x 10 mm, PWM, 800 - 3300 rpm

More tests.

	Pentium G620	Pentium G620 @2.2GHz	Pentium G620T
Idle	39W	39W	39W
BD playback by PDVD11 (DXVA)	43W	44W	43W
DVD playback by PDVD11 (TrueTheater HD)	47W	47W	47W
x264 HD Benchmark 2nd Pass	60W	56W	58W
Prime95	64W	58W	61W
FurMark	54W	54W	55W
Prim95+FurMark	76W	71W	71W

Pentium G620T (at least mine) is just Pentium G620 with clock multiplier limited to 22 (100MHz BCLK x 22 = 2.2GHz).

	Core i3-2100	Core i3-2100 @2.5GHz	Core i3-2100T
Idle	39W	39W	38W
BD playback by PDVD11 (DXVA)	44W	44W	43W
DVD playback by PDVD11 (TrueTheater HD)	56W	55W	56W
x264 HD Benchmark 2nd Pass	72W	63W	64W
Prime95	74W	64W	65W
FurMark	55W	55W	54W
Prime95+FurMark	88W	77W	72W

Core i3-2100T is more or less identical with Core i3-2100 with clock multiplier limited to 25 (100MHz BCLK x 25 = 2.5GHz), except for Prime95+FurMark.

Wow, BD playback is "greener" than DVD playback!

DVD was played back in TrueTheater HD mode to see how the power consumption is when CPU is used for decode/post-processing (I should have added a comment). The power consumption at DVD playback in DXVA mode is more or less the same as BD playback.

OK, makes (more) sense!

Thanks a lot for these Rene. Really shows that these low power chips are pointless. Aside from the cooler of course. Good to know.

I got roughly the same numbers for idle 35 to 40 w and BD playback 40 to 45 w with: Seasonic x660 PSU, Intel DH67DG system board, i7-2600k 3.4 gigs turbo boost disabled, 8 gigs ram, 2.5 inch 500 gig 5400 rpm system drive, 2 tb WD green data drive. Liteon iHBS212 Blu-ray burner. It has probably gone up a little since I added the second data drive and the Hauppauge 2250.

I wanted to chime in and help re-inforce that these new sandy bridge pentium chips are a tremendous value for an HTPC. I just finished a build the other days that consisted of:

Pentium g620t
Asus P8H61-I REV3 mini-itx
2gb ram
30gb OCZ onyx ssd
Antec isk-65 case with stock psu

So quiet! The lack of hard drive searching noise is so noticeable, especially sitting next to my 6 year old gateway laptop. So far, it has ripped its way through every torture test I have thrown at it. It will be replacing a 4 year old popcorn hour a-100 streamer, that did its job valiantly, but stumbled on some 1080p bd rips. The same ones that caused the popcorn hour to hiccup are like a warm stick of butter to this hot knife of a machine.

Also, it idles at 22 watts, peaks at 39 during boot and topped out at 53 on prime 95+furmark.

renethx: can you tell me which pcie x1 card you were able to get working in your ASRock H67M-ITX? I just bought this motherboard and it refuses to see my AverMedia Duet A188 TV Tuner.

That's not true at all.

Where did you read this? I have used the 2100t CPU heatsink probably 6 times and its phenomenal. It also seems to have more blades than the 2100 CPU and heatsink.

I can tell you that if you want the 2100t for its low heatsink fan then you should get it. Its solid.

If you can get the 2100 for $99 at microcenter and then get an aftermarket low profile like the ones renethx mentioned then that is a great idea as well.

"Where did you read this?"

At AVS Forum, where a number of posts have described it as "loud" or "quite loud". I have a Microcenter nearby, and was tempted to drive there for a 2100 for $99, but I find no evidence the above-linked Gelid cooler is actually for sale in the U.S. so I'm not as excited about going 3rd party since the Thermaltake cooler was reviewed and called more or less one of the worst coolers ever and there is but one review of the Scythe, which describes it as not noisy, but lacks a lot of the kind of testing I like to see.

The majority opinion on avs is that the stock coolers work just fine and are plenty quiet for typical htpc duties.

I agree my i3-560 cooler is damn near silent.

Got my new MicroCenter sale flyer yesterday. The $99 for the 2100 is continuing until at least June 16.

I'm not disputing that assassin. I'm more of the SilentPCReview crowd I suppose. I don't want to hear the computer. I don't want the computer to get noisy on a warm day. And based on those that don't care for the 2100t cooler, I'm suspecting I won't care for it either.

Regardless, the fact that the replacement coolers are more or less non-options (except the Scythe) limits the choice matrix.

Gelid Slim Silence i-Plus is in stock at Directron.

Good catch Rene, I went through more than a dozen of the vendors on their site only to not find it even listed....

Google turns up no actual reviews of it however.

I found it by Google Product Search.

Slim Silence i-Plus is close to Slim Silence 775. There are lots of reviews of the latter.

Yes, that's the primary reason I chose it for my build in a Habey EMC-800b - the standard i3-2100 cooler would likely not fit.

I'd have to add this one to the list that I am very happy with:

37mm
SilverStone Low Profile 90mm Fan CPU Cooler for LGA 1156 Platforms NT07-1156

Pointless is probably a step too far. If buying an itx board not rated for the 95W CPUs or for those who value convenient/guaranteed performance imo it is worth a small premium.

Nice analysis, thanks for doing this.

Given the basic configuration:
- Pentium / Core i3 processor
- H61 mb
- 2 x 2GB DDR3
- 1 x 3.5" HDD
- PSU
I expected to see lower idle power numbers. To what do you attribute the relatively high idle power? The MB, PSU, both?