HTPC GuideZertz , technodanvan , tacohunter52 - March 15, 2009
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The CPU Heat Sink:
Although the CPU is arguably the most important part of any rig, you're going to need a way to keep it cool. If you purchased a retail CPU (as opposed to an OEM), it will come packaged with a heat sink. These are only adequate at best and really aren't designed for performance in any sense of the word. An aftermarket heat sink is almost a necessity for any new computer - in an HTPC it is even more important. Stock heat sinks are not only inefficient at removing heat, they tend to be noisy. With just a bit more money you can drastically improve the temperatures, as well as the noise of your computer. For the lowest end processors you may argue that it wouldn't be worth buying a new heat sink. You may end up spending nearly as much on your heat sink as on the processor itself!
To me, spending an extra $30 for a heat sink that ensures I can listen to some nice quiet music without interruption is $30 well spent. That doesn't even take into account how much cooler the processor will run. Based purely on noise alone, it's money well spent. Remember, that one of the main purposes of this machine is to play back movies. Even the bloodiest action flick has quiet moments that will reveal any fan noise your computer makes. It may not sound like a big deal now, but if you're unfortunate enough to experience it, you'll be very annoyed.
While there is always the possibility of passively cooling a CPU, I would not try it. It could work, but the probability is that you'll end up melting your CPU like ice cream in a microwave. If you manage to get a passive heat sink that works enough to keep your processor running under 50C even under load, something along the lines of a Thermalright Ultima-90, cool! You could drop 10°C from that by simply adding a low-speed fan, cooler. A decent fan at low speeds won't produce any noise worth mentioning, and the benefits of a cooler, happier CPU are gained as well. I really can't see any reason to run a passive system. If you know what you're doing it can be done, but for the same price you could run a cooler, more efficient system, coolerer!
Anyways, back to the heat sink discussion!
In the last few years there has been a veritable explosion of heat sinks on the market. Companies such as Thermalright and Zalman have built their reputation on these products. Larger, more diverse companies such as Asus and OCZ have branched off and added heat sinks to their product list. Many smaller companies have sprouted up as well, in order to try their hand in the market, with mixed results. From perhaps hundreds of available heat sinks a few stand out from the rest. These I'll list here. But keep in mind that buying the correct heat sink can sometimes be a real pain. A few things you should think about:
- Ensure the heat sink you purchase comes with the mounting bracket for your processor. For the purposes of this guide, LGA775 and Socket AM2 are the only ones to be worried about. However, not all heat sinks come with brackets for both Intel and AMD. If you see a model that appears to be perfect for your rig but notice it doesn't come with the correct hardware to mount it, don't give up hope. Check out the home website for the heat sink in question. You may find they offer additional models not listed on other sites. Shoot them an email if nothing else. Sometimes you'll get lucky.
- You will likely be limited in height. If you're using an HTPC-style case you may have less than 120mm to work with, and this will narrow your choices down a bit. The best, most efficient heat sinks are the big ones. The Thermalright Ultra-120 Extreme and the Zalman CNPS-9700 are absolute monsters and sometimes don't fit even in big cases! Double check the height of the sinks and the available space in your case. If it won't fit, many times you'll see a smaller variant of the same sink that will. If you have an especially low-profile case you will probably have to accept that your processor will run warm, but there are still relatively inexpensive heat sinks that are quiet and cool fairly well, even with reduced space.
- If going for a shorter heat sink you may use one that utilizes the “flower-style” design which uses a fan pointing straight down at the board. While still good sinks, these are notorious for not working with all motherboards due to width restrictions. Check the spacing around the CPU socket to ensure it won't interfere with your memory, Northbridge heat sink, or any capacitors nearby. Some taller heat sinks also can have this problem, though usually they can be turned in a way that they don't interfere with anything. Many times heat sinks that are known for this problem have compatibility guides at their official site. Otherwise ask around in the forums.
- Watch the weight of your heat sink. In an HTPC-style case this is usually a non issue but some people won't be using one. Heavy heat sinks can put a lot of strain around the CPU socket when installed in a vertical case. At best this will just cause uneven cooling, meaning one core may run warmer than another. At worst it could tear free from the board.
- Most sinks are made of aluminum, copper, or a combination thereof. Copper conducts heat better than aluminum and is typically used in the base of the heat sink. Some heat sinks utilize copper throughout the design. They generally cost more and certainly weigh more. Though it doesn't conduct heat as well as copper, aluminum is inexpensive and is much lighter. Many companies use aluminum fins in an effort to reduce both cost and weight. Some inexpensive heat sinks use aluminum for the entire design, including the base. As both Intel and AMD use copper in the base of their design, I shy away from all aluminum models.
- Lastly, most HTPC cases offer extremely poor airflow. This is a given, and we have to accept it. However, choosing a heat sink with a vertically mounted fan, if oriented correctly, will help improve the flow of air through the case. Horizontal designs will help keep air flowing over nearby components but won't do much to keep air flowing through the case. While one isn't necessarily preferred over the other, it's something to think about, especially if you don't intend on modding the case to improve airflow initially.
Okay, now that that's covered, here are my choices and a few words about each:
The standard height of an HTPC-style case seems to be around 120mm from the motherboard to top of the case, so I will choose heat sinks that are a little bit shorter. Some cases have support brackets crossing in the same area, reducing maximum height to only around 60mm. These brackets are usually unnecessary and should be removable with a screwdriver. Most of the sinks listed here are short enough to work with the bracket. However, I expect most people to remove it, so this is not a defining criteria.
- Evercool Buffalo: While this may not be the greatest cooler it does meet the requirements, and it can cool a good 10°c better then a stock cooler.
- Asus Triton 77: This cooler seems like it was made for an HTPC case. The fan is hidden, it isn't very big, and temperatures greatly increase with an overclock - this is perfectly fine because you probably won't be overclocking your HTPC.
- Coolit Pure:This cooler is a mixture between air and water cooling. It meets all size requirements, and may be your best bet for a silent cooler.
- CoolJag Falcon 92: This is another heat sink that could have been made for an HTPC. It is both small and efficient. The fan fits inside the cooler itself. This heat sink is comparable to the TRUE, and should definitely be considered for any HTPC build.
- Scythe Ninja 2: This cooler is aluminum with a copper base. It's not the best heat sink, and it's not the worst. That definitely makes it an option.
- Scythe Shuriken: This cooler is slim, and does a pretty decent job at keeping your CPU frozen.
- Thermaltake SpinQ: This is possibly the coolest looking heat sink ever. Although it is a bit bulky, it should fit in most HTPC cases.
- Thermolab Baram: This heat sink is thin enough to support two fans, it cools about the same as the Scythe Ninja.
- Thermolab Micro Silencer: This heat sink is the smallest of my choices. It's not great, but it out performs the stock HSF, and you'll have no problems fitting it into a tight space.
- Titan Cool Idol: This is a great heat sink, it performs just as well as the TRUE and the V8.
- ZEROtherm Zen: This is another great cooler. It is thin, good at cooling, and definitely a choice to think about.
The following are heat sinks that offer absolutely stunning performance but are probably too large to fit into a typical HTPC-style case. The heat sinks above could be used in a normal case of course, and depending on your processor there may be no reason to get anything bigger listed here. However, for those running quad core processors these definitely warrant a hard look.
Again, I want to stress that just because I say these are great heat sinks doesn't mean they are your only choice. Many other heat sinks are available and may prove to be a better option depending on your CPU and case choice. Also, you should purchase an aftermarket thermal paste to go with most of these. I always use Arctic Silver Ceramic and highly recommend it to anyone that is new to computer building. It's very easy to use and still ranks among the best you can buy.