Originally Posted by Sin0822
Now to Kitguru's sad attempt to get hits. LOL I mean if you don't know what kind of caps those are you really shouldn't ever comment on them like you know what is going on!!! haha it is too funny.
First of all the GIGABYTE Z77 boards they have NO ISSUEs OCing at ALL. The GB boards surprise under LN2 too in pure frequency(seriously take it for a spin, many LN2 OCers use them), IMO bring it on, these boards have no issues with CPU OC like someone stated they heard a few pages back.
As to the lack of multi-layer ceramic (MLCC) capacitors on the back of the board, there is a reason for why some board makers use are both types of capacitors, that reason is that part of their VRM needs the use of high frequency ceramics which have low ESR, while other VRMs don't because the ESR and speed of their VRMs are good enough without them. The capacitors in general act as large energy storage, in normal operation there are huge swings in current, and the rate at which that current can be provided to the CPU as it changes load states is extremely important. That is why there is an output capacitor bank. It can sink or supply power as needed. However the caps have to charge and they have to discharge, so in general two types of capacitors are used, ceramics which are extremely small are good at operating at high frequencies and have very low capacitance. Electrolytic ones are those that look like cans, they also have higher ESR as well as high capacitance ratings, they generally also don't operate at high frequencies.
ESR=effective series resistance
ESL=effective series inductance
Basically just like MOSFETs(MOSFETs can be thought of as having capacitance and resistance), capacitors have parasitics which are characteristics one wants to minimize in the capacitor. Inductance and resistance are two very big ones, which hinder a capacitors performance. Higher ESL and ESR usually isn't what you want. To get over this manufacturers use a mix of the ceramic and aluminum electrolytic. Sometimes manufacturers will use tantalum to replace some ceramics and electrolytic. It all depends on the rating of the capacitors, but really the price of the capacitors they want to use and the amount of them. If you pay more you can get lower ESR and ESL capacitors, if you pay less you will need to use other methods to prevent performance issues. The most commen method is to use a mix of caps, however GB chose to flip the bill and just use their electrolytic, why? Because simply they can as their caps have very low ESR.
Now when a VRM works each phase provides some current and all that current is provided to the CPU as a whole, each phase however operates while the others are off, and so in a 6 phase VRM each phases is on for 1/6 of the time, however they switch on and off hundreds of thousands of times per second. In normal operation the inductors and capacitors work together to provide steady power to the CPU as the power is provided to the inductors, and the inductors to the cpu and capacitors. However if there is a big load, the VRM isn't prepared and will have to depend on the energy stored in the capacitors to take over the entire load while the rest of the VRM can respond. Also after a large event the VRM has to recover and depends on the capacitors to sink the extra energy. Basically the capacitor bank is slow and thus limits the system transient performance. Thus the characteristics of the capacitors used needs to be taken into consideration. A mix of capacitors needs to be used to make sure a few things happen. #1 that the output voltage doesn't deviate from what the designers want during a large load, #2 so that the power can be provided quickly enough #3 as much power as is needed can be provided and there are more things, but those are the three important ones for this conversation. The ESL and ESR are the two characteristics of the capacitors that affect their performance. On the ceramics one must minimize their ESL so that they can properly support the output voltage and make sure it doesn't deviate, and the electrolytics needs to have their ESR low enough to minimize the voltage drop from increased current. However you don't needs to use any electrolytics, take for example some volterra VRMs, they have little to no can type capacitors. You will also have boards on the other which will will have extremely well speced aluminum electrolytic which are in fact good enough to work without ceramics, such as these boards. These GB electrolytics have better ESR than the majority of tantalum capacitors, as so someone told me.
Perhaps ASRock is angry that they don't have any digital PWm supplier and are thus trying to make it seems like GB sucks lol.
FYI ceramics are cheap as hell, GB would put them on if they are needed. However it looks like they are not.
I think fasty explained it well enough.