October 25, 2009

We take a break from our overclocking series this week to take a look at an important component of every computer build; the power supply unit, or PSU. While at first glance this component may seem pretty straightforward, there are actually quite a few nuances that make selecting the best power supply a little tricky. It is not enough to simply pick the one with the most power that you can afford; rather, there are some key specs that you should watch for and select based upon.

As with most components, one of the most important considerations is brand reputation. While it is possible to get a bad power supply from any manufacturer (it sometimes just happens), selecting a PSU made by a quality, well-known company with a good warranty and reputation will greatly decrease the chances of receiving a DOA unit, due to the resources they devote to quality control during the manufacturing process. Corsair by far consistently gets the best ratings and reviews, and makes some exceptional power supplies. Some other leading manufacturers include PC Power & Cooling, Antec, and OCZ. However, this doesn't mean you have to pay a ton for a quality power supply. With the abundance of sales and mail in rebates available, it is not too difficult to find an excellent PSU for a good price.

Once you have established a budget and have narrowed it down to a few good brands to look at, it is important to evaluate your needs and select the best PSU you can afford based on that. First it is necessary to decide how much power your system actually needs. An excellent PSU Calculator can be found here, or you can do an online search for a similar calculator and get a second opinion. Newegg's calculator can be found here. Select the components you have or will use for your build, and then consider giving yourself a little headroom for future upgrades. For modern computer systems, 400W - 500W will be more than adequate, unless you are planning on running multiple video cards in SLI or Crossfire configurations for gaming. If so, add 150W - 200W per video card.

There are only a few other key considerations to look at. If you are planning on running multiple video cards as mentioned above, you also need to make sure your power supply has enough cables to support it. While it is possible to use adapters in some situations to give you the extra connectors you need, it is better by far and will result in more stable power distribution to simply select a PSU that has the required number of connectors to begin with. Most video cards use the PCI-E cable (check your documentation to be sure), so you will want to ensure the PSU you select has enough of these cables to accommodate the number of video cards you plan to run. Additionally, some power supplies are SLI/Crossfire "Ready" or "Certified" and it may give you more peace of mind to select one of these if you are planning on running such a configuration.

Another important point is to ensure that there are enough amps on the main +12 Volt rail to support your system. The explanation of what that means and why is pretty technical, but what it means to you is that when you are looking at the specs for your shiny new PSU, you want to make sure you have one with a high amp rating on the +12 Volt rail. This will usually be listed in the detailed specifications of the item description. While you'll get a number of different opinions on this, in general 20 amps is a good number to shoot for, and I would be hesitant to put anything less than 18 in anything I build. Where this comes into play is with the popular multi-rail supplies which advertise 4 or more +12V rails. While this sounds great at first, when you dig deeper you usually find out that each rail is only rated at 14 amps, which can cause instability in any system and would definitely not be sufficient for your high-tech video card. Find one with a single +12V rail rated at 20 amps or more (30 to 40 amps are not hard to find). The image the right is from a Newegg product page and shows what you are looking for.

Finally, there is the debate on modular versus fixed power supplies. Modular PSU's allow you to only connect the cables you need to use, which results in a much cleaner installation and build. Fixed cable supplies don't give you this flexibility, but have less resistance and result in larger amounts of cleaner, more stable power being supplied to your system. I use fixed cable systems in all of my builds, but the choice is up to you.

If you are worried about energy efficiency it is possible to buy more efficient power supplies, including ones that are certified "80 PLUS" or more, which means they are always at least 80% efficient. Make sure the power supply you buy also has enough power cables for the number of hard drives and optical devices you plan to connect, and finally, make sure the dimensions will fit inside your chosen computer case. : )

(Images courtesy of Newegg.com.)

October 19, 2009

Now that you have the tools you need and are at least slightly familiar with what they do, we can take a closer look at where you will work your overclocking magic: your motherboard’s BIOS. The “Basic Input/Output System” of your computer is the permanent (well, sort-of*) set of instructions that your computer relies on to do anything, regardless of the hardware you plug in, the software you install, or even the operating system you are running.

(*It is possible to replace or upgrade your BIOS by a process called flashing. However, if done incorrectly you can easily render your computer inoperable, so it is highly recommended that a professional perform this procedure. In general, flashing your BIOS is not required, however, it can sometimes be necessary if your motherboard’s manufacturer releases an updated version that fixes a problem or provides improved hardware support.)

As you may have surmised, the BIOS comes pre-configured on your motherboard, and you probably weren’t even aware of it until you started learning about overclocking. It isn’t designed to require frequent interaction. However, it is what controls many of the hardware settings you are interested in for overclocking, and so you will be spending a significant amount of time there from now on.

To get into your BIOS, you will need to reboot your computer. As it is booting back up, there will be a key to press that will open it up. Usually there will be a message on the screen indicating something along the lines of “Press DEL to enter Setup.” This is what you want. If you time it just right, you only have to hit the key once, but I usually have to hit it a couple of times to get it to register and start loading the BIOS, which is usually indicated by a message along the lines of “Entering Setup.” As every motherboard and BIOS is slightly different, you’ll have to figure out what key you need to press. It may be Delete, or it may be an F-something Function key.

Once you have entered setup, you should see a screen something like this. Like I mentioned, every motherboard is a bit different, but they follow the same principles. What you are looking for are the advanced setup options for your CPU that allow you to set the Clock Speed or Ratio. There are a lot of other settings you can tweak in here, and messing with them has the potential to cause your computer to crash, or even cause physical damage to your CPU or motherboard. For now, tab through the different sections in your BIOS and get familiar with what is there and where everything is. If you don’t see any settings you can change for your CPU, then chances are your motherboard will not support overclocking. This will be the case for older motherboards, and any that are OEM, or original equipment that came with a store-bought PC such as a Gateway or Dell. Also, if you’re trying to overclock your laptop, chances are it won’t support it.

Next time we will have a look at the key settings you will be changing, and what they each do, as well as an overview of the process. Until then, another thing that would greatly improve your understanding and ability is to read the manual that came with your motherboard. Generally, most newer motherboards have excellent overclocking support, and the manual will tell you what each of the settings do. Understanding this will help you know how the instructions given here translate you your particular motherboard and BIOS.

(Image courtesy of Thomas Soderstrom at Tom’s Hardware.)

October 5, 2009

Continuing our series on overclocking, today we have a quick rundown of the software utilities you’ll need to be familiar with. Before you even start messing around with anything in your BIOS, you will want to make sure you have these tools ready to go.

First of all, you’ll want to download Core Temp here.

Get the latest version (as of this posting 0.99.5) in either 32-bit or 64-bit depending on your setup. This simple tool is vital to making sure you don’t toast your processor, and also provides some other key information such as voltage and processor frequency. It will look like the screenshot on the right when run, and provides separate temperature information for each of your cores if you have a multi-core processor.

(BONUS TIP: If you have one core that is significantly (i.e. more than a few degrees) hotter than the rest all the time, you probably didn’t put your thermal compound and/or heatsink/fan on correctly. Remove both and try again, being sure to seat your cooler properly.)

Secondly, grab CPU-Z from our friends at CPUID.

This handy tool provides more in-depth information than Core Temp, and also lets you check such other vitals as your memory speeds and settings. It is also available in both x86 and x64 flavors, and looks like this:


While you’re visiting cpuid.com, grab HWMonitor as well.

This provides much more in-depth information about all of your systems operating temperatures and voltages, including min and max values for as long as the program is running. This is vital for when you are stress testing your processor and want to see the maximum temperature reached, not just the current temp. It also provides temperatures for your video cards and hard drives which can help you determine if you have adequate ventilation in your case. HWMonitor looks like this:


Finally, head on over to mersenne.org to download Prime95.

No, you’re not going to be calculation Mersenne Prime Numbers (although you can if you want). Instead, you’ll be using the “Torture Test” capabilities of this program to stress your overclocked CPU and ensure stability at acceptable operating temperatures. The most recent version (v25.9, March 2009) looks like the screenshot to the left when run. On the website, just skip down to Step 3 and grab the utility, and make sure you get the 64-bit version off to the right if you’re running an x64 system.

Well, that’s it for now! Download these tools and have them easily accessible, and you’ll be ready to start tweaking your BIOS settings and sending your CPU into warp! As part of the continuation of this series, we’ll cover these tools and how to use them in more detail later.

(Images courtesy of MyPCReborn.com.)