CoolerMaster Gemini II S fanless?

[jaydee]

Does anyone with experience or expertise, know if it's fairly safe to run a fanless Gemini II S on a Core i5-750 or i7-860 in a case with good airflow? From what I understand, the Gemini II (no S), came fanless because it could keep lower powered LGA775 chips cool enough passively with decent case airflow. Thanks!

<--- relative noob with cpu hs/f's.

 

[SunnyD]

The Gemini II and the GeminII S are two completely different sinks.

The Gemini II is a (pardon the french) FUCKING HUGE heatsink that fits two fans across the fins. The GeminII S is a single 120mm lower profile heatsink. I would say that it is definitely not safe to passively cool an i5-750, and definitely not a i7-860, especially if overclocked.

For what it's worth, I was looking into the GeminII S to fit in a slimline mATX case.

GeminII S - Dimensions: 124 x 118.4 x 62mm

Gemini II - Dimensions: 175x124.6x81.5mm

 

[jaydee]

Gotchya. Although I thought the i5-750 and i7-860 had similar power draw, no?

 

[SunnyD]

Gotchya. Although I thought the i5-750 and i7-860 had similar power draw, no?

Yes, but the i7-860 also has HT, meaning slightly more power and a good bit more heat, especially if you're overclocking.

 

[jaydee]

So would the original larger CoolerMaster Gemini II be ok fanless with the i5-750 or i7-860? I'm not interested in overclocking, if anything I'm more interested in undervolting if it could be done with stock clockspeed.

 

[SunnyD]

So would the original larger CoolerMaster Gemini II be ok fanless with the i5-750 or i7-860? I'm not interested in overclocking, if anything I'm more interested in undervolting if it could be done with stock clockspeed.

I would say a resounding NO.

Personally, I don't think any air cooler would be suited to run fanless on an i5-750 or i7-860, even in a wide open case. In the case of possibly ducted airflow, you're still going to have fans moving air, so what would be the point?

I'm sure it could be done if undervolting, possibly underclocking a bit, and a really good air cooler with decent air flow, but I think your temps would be unreasonably high under load. At least for me, I would be scared to run like that.

FWIW, I run an undervolted i7-920 D0 slightly overclocked with a Core-Contact Freezer and a 120mm fan. My temps idle around 50C (+/- depending on ambients - right now mid 50's because it's about 15F warmer in the house now that the weather has turned good). But I have arguably worse case air flow with an Antec P180.

 

[jaydee]

Ya, I previously skimmed the article, but they didn't test any fanless configurations, so...

I won't risk it by going fanless (if/when I do buy), thanks for your input. I was curious "just because", nothing that would necessitate.

 

[SunnyD]

Ya, I previously skimmed the article, but they didn't test any fanless configurations, so...

I won't risk it by going fanless (if/when I do buy), thanks for your input. I was curious "just because", nothing that would necessitate.

Well my suggestion is get something with a 120mm fan, run it at low speed. To be perfectly honest, I have an i3-530 with a retail stock cooler that I am running via PWM. It's loud as hell on full speed, but once PWM was calibrated it's near dead silent and the temps aren't terrible either. If you have room for a big cooler, get a good quality sink and run at low fan speed. Hell, you might want to take an hour and run it sans fan in the process to see how that works out. But a 120mm fan running low speed should be "good enough" to keep your temps "reasonable" without too much noise.

 

[alyarb]

you can't run a fast CPU passively. the way to do it silently is to get a high performance heatsink like a noctua, TRUE, mega shadow, etc. Run a pair of 120mm fans in push-pull and turn the voltage down until you simply can't hear the fans anymore.

the air is still moving, but you can't hear it. this is 100000&#37; better than still air.

 

[jaydee]

Well my suggestion is get something with a 120mm fan, run it at low speed. To be perfectly honest, I have an i3-530 with a retail stock cooler that I am running via PWM. It's loud as hell on full speed, but once PWM was calibrated it's near dead silent and the temps aren't terrible either. If you have room for a big cooler, get a good quality sink and run at low fan speed. Hell, you might want to take an hour and run it sans fan in the process to see how that works out. But a 120mm fan running low speed should be "good enough" to keep your temps "reasonable" without too much noise.

I was thinking Silverstone SG05, so very little room above the CPU; something like 83cm of clearance.

 

[SunnyD]

I was thinking Silverstone SG05, so very little room above the CPU; something like 83cm of clearance.

Well, the GeminII S actually caught my eye because it's actually a really good cooler (with the fan), and pretty damn quiet too (according to frostytech at least). Definitely better and quieter than the Big Shuriken (53mm tall), especially at low speed.

I'd say yeah, the GeminII S will fit your bill. The fan supports PWM, and the way it sounds like you'll be running your system it should actually work out well for you. Worst case scenario is that it's a little louder than you want, you go and find yourself a different 120mm fan that will run even slower and quieter.

I'm still looking at getting one myself, but I haven't done clearance measurements for the machine it would be going in yet.

 

[jaydee]

How do you adjust the PWM? From the BIOS, or are you talking about a hardware knob?

 

[SunnyD]

How do you adjust the PWM? From the BIOS, or are you talking about a hardware knob?

In this case, it's a PWM capable (4-pin) fan, so from the BIOS.

As an example, the stock retail cooler that came with the i3-530 is a PWM fan. Plug it in, it runs full blast. Go into the BIOS (on my mobo), there's a setting to "calibrate" the fan. It starts, and then steps through the settings automatically and stores the respective start and stop numbers for the fan which indicate its voltage range. Then it turns on "Automatic" fan control, and done - silent until temps start going up.

 

[alyarb]

there are plenty of windows apps that allow PWM control as well.