Alpha 400 full speed is 2800, the noise is a little big is normal
Since you do not care about the noise that is fine, because it seems to be online speculation is that the Alpha 400 is the perfect match for the 9550
.The second is OC3's Weihai HP-1036, designed for HTPC and has OC3's HDT technology, which is estimated to be less noisy than the Alpha 400
Other than that, I've looked at this price point and I don't have a choice
Now, most of the good ones are side blown + heatpipes, and there aren't many choices of direct blowing, so I think you can go with a side blown + Northbridge active radiator, and that's a great choice.
There are a number of options to choose from, including the side-blown OC3 Red Sea series, the Kyushu Windshen Ice Ling 400 Black Jade, and a bunch more
To be effective, the Alpha 400 should be better, and quieter, the Weihai is better
But given that you can't overclock the Weihai, it's better to go with the Alpha 400
I've seen the Alpha 400's design, and the general design of the motherboards. 400 design, the average motherboard can still fit, known conflict boards are Gigabyte ep45 UD3R, Gigabyte EP43DS3L ...... seems and Gigabyte can not get through? （
(Just saw your motherboard model, wait for me to observe)
Should be able to install ...... but I'm not so sure
Additionally recommend two slightly higher-end point of the downward-pressing fan
Jiujhou Fengshen Icewing 5 and jiujhou fengshen black killer whale
A ￥ 210 or so, and a ￥ 260 or so
If you're not short of 100 bucks, these two are absolutely great
And because the heat pipes are designed to lead out, there's absolutely no chance of them clashing with the capacitors
These two fans are the most powerful in the world.