SilverStone Raven RV05

[GraysonPeddie]

PXE booting is not that easy to setup, especially if you have to setup NFS for booting into a live environment.

For those 5.25" drive bay advocates, I hope one day compact discs will be very common for you and burners will be smaller, too. But then Macs do not have optical disc drives at all.

[Luke]

I hope all cases never follow this example.

I too use 5.25 bays to hold hotswap RAID enclosures, and I often use DVD's to have video clips to someone who won't be able to offload them on the spot into a laptop and give back the flash drive. I cannot afford to give away that many flash drives-and with things like BadUSB out there could not trust them after they were returned.

Cases with no drive bays I would have to avoid or else make the bays myself, as I have often done when modifying a case to hold more drive bays. I often find myself using a 5x 5.25"/1x 3.5" or a 4x5.25"/2x3.5" configuration, with the cases I can afford that means adding bays, not subtracting them. On steel cases torch soldering tab and screw joints can give great stiffness and durability, on all-aluminum cases I have to get much more creative with the small screws. If I'm not after aluminum some of the early full-tower cases from the Pentium II/ Pentium III era give a good starting point, it's a lot easier to add fan holes and grates than to add drive bays. Main issue with those is having the PSU on top breathing all that hot air. Best thing is that the full towers use removable side panels and a permanent top that can accept steel carry handles, yet they don't have all that plastic crap you see on a lot of newer OEM cases and are made from much thicker steel than cheap tin cases today,

Only one of my cases (a Diablo Fly) started life as an aftermarket case. I wanted brushed aluminuim and was out of cases anyway. Flexy as hell in a machine with a heavy cooler and a RAID subcase. If I wanted to move that machine around a lot I would have to add corner gussets of 1/16" or 1/8" plate, I only have much of the latter in my shop. Also would have to reinforce the motherboard tray, possibly copying that old Dell design where the CPU cooler backplane bolts go through an extension of the tray, but keeping the original MB backplane as well to ease the insulation issues. None of my cases use side windows, as they leak buckets of RF that can jam some wifi devices (yes, I tested this!) and also possibly be used for surveillance (TEMPEST). I want metal, not plastic, across all the RF exits from the case, I spent enough time screwing with radio to be well aware of RFI issues. I had to screen the large back of case fan exits to stop RFI from jamming one of my wifi devices, in fact, due to the cooler acting as an antenna.

All these manufactured cases ought to be using fine wire screening embedded in or just behind any windows, it could be black anodized behind smoke color windows to keep it out of sight. Other alternative is mesh side panels, they cool better too but leak sound instead of RF.

[stqn]

None of my cases use side windows, as they leak buckets of RF that can jam some wifi devices (yes, I tested this!) and also possibly be used for surveillance (TEMPEST). I want metal, not plastic, across all the RF exits from the case, I spent enough time screwing with radio to be well aware of RFI issues. I had to screen the large back of case fan exits to stop RFI from jamming one of my wifi devices, in fact, due to the cooler acting as an antenna.

All these manufactured cases ought to be using fine wire screening embedded in or just behind any windows, it could be black anodized behind smoke color windows to keep it out of sight. Other alternative is mesh side panels, they cool better too but leak sound instead of RF.

That?s something to keep in mind, although I?m pretty sure I had a lot of wifi problems even when my PC was in a fully enclosed metal case (Antek ISK 310-150). My current case is half open on one side for ventilation purposes (it?s an old case with basically no air input) and wifi is working fine, but I have my antenna one good meter away from it.

On the topic of noise, I?m glad that nowadays you can have a powerful computer that makes very little noise if you choose your components well. The worst offender here is my 3.5" HDD (WD Red).

[Luke]

Chokes on cables needed as well as tight case for RFI issues

That?s something to keep in mind, although I?m pretty sure I had a lot of wifi problems even when my PC was in a fully enclosed metal case (Antek ISK 310-150). My current case is half open on one side for ventilation purposes (it?s an old case with basically no air input) and wifi is working fine, but I have my antenna one good meter away from it.

On the topic of noise, I?m glad that nowadays you can have a powerful computer that makes very little noise if you choose your components well. The worst offender here is my 3.5" HDD (WD Red).

RFI can get out of even the best case by following a cable, and some cables, notably older style monitor cables make noise of their own. Monitor cable RFI is the worst, as it can potentially allow someone to reproduce what is one your screen (this has been demonstrated before). RF chokes on the cables, known to hams as "common-mode chokes" go a long way to reduce this, that's what that cylindrical lump on a good cable is. You can add your own to other cables such as microphone and speaker cables.

In times before these chokes existed, amateur radio operators had the devil's own time keeping RFI from transmitters and RF amps from getting out by power supply leads, etc. Usually harmonics of their intended signal, they would jam TV broadcasts if not stopped. Oftentimes shielded cables had to be used for DC from separately cased power supplies, and the use of coaxial cable to antennas or other RF units kept rfi from flowing out the back of the case and along the cable by grounding the shield all the way around.

Today, no computer case ever features metal grounding to a shielded cable all the way around each and every cable connection, relying only on the common mode chokes. People who run computers alongside ultra-sensitive ham radio receivers had no end of trouble in the past when computer frequencies were lower and hit more ham bands, sometimes turning to old IBM server cases as among the most RF-tight that could be found. On my rig, the issue is this: the hypertransport and the wifi are both at 2.4 GHZ, meaning if the HT frequency gets out of the case it will jam the wifi and cut off my Internet access. The stock fan grate on a Diablo Fly was too restrictive and would not handle the cooler's airflow and had to be replaced with a much more open "fingerguard." The cooler back fan is ducted directly to that opening and is just inches away. Studies done by Intel during the Pentium III era found that the CPU cooler often becomes coupled to the chip for RF and acts as an antenna. In this case it was like a 2.4 GHZ radar antenna pointed at the biggest hole in the case and through it at the wifi antenna. The result was no connection but my own would show up, and it would drop in and out from all the RF racket. The workaround was a cable to get the USB wifi device away from the case, the fix was a screen under the case rear fan outlet, which was just a fingerguard.

If you look at old cases from the Pentium III era you see much better attention paid to RF shielding than now, often with metal grounding fingers to make good contact with metal liners under plastic case components. Remember that the 133 MHZ front side bus of the fastest Pentium III chips was inside the aircraft band.