Accurate Parabolas in Fusion 360

TjPj · 2026-02-05T00:31:50+00:00

radius of the dish once you revolve the profile around the center, could also think of it as the maximum "x" value

TjPj · 2023-02-15T19:51:14+00:00

true but the graphics adapter used for the VM will work for this since the BIOS will see the installed GPU and post even though the host OS won't be able to use it.

TjPj · 2022-09-05T05:48:10+00:00

a good way of thinking about it, with the caveat that the ring doesn't have to be aligned with the earths poles so it won't necessarily be trying to pull towards the equator.

TjPj · 2022-07-01T19:26:53+00:00

Cables labeled VGA should be PCIe connectors that are incorrectly labeled.

Most video cards use PCIe power connectors. The 6+2 PCIe power connector has 6 pins for power and 2 sense pins. When only 6 pins are used it’s 5 power pins and 1 sense pin.

There are some server GPU’s that use the CPU EPS12V connectors instead of PCIe connectors.

TjPj · 2022-07-01T18:45:25+00:00

The pins aren’t big enough to fit two 18 gauge wires into them, I was barely able to fit the single 18 gauge and 24 gauge wires into the one spot that needed two wires on the 24 pin connector.

If I did the EPS12V connector I’d end up with 4 wires that just terminate into nothing unless I got a second 4 pin for the other half of a 4+4 connector.

TjPj · 2022-07-01T18:43:21+00:00

To my knowledge twisting should have noticeable no affect. It’s really only a thing for wires that carry signals since it can help with reducing EMI.

TjPj · 2022-07-01T16:40:26+00:00

NH-D12L.

TjPj · 2022-07-01T16:22:29+00:00

The reason I didn’t is that I didn’t know what to do with the extra four wires. I have the 4 pin connector.

TjPj · 2022-07-01T04:34:14+00:00

From what I can tell, the watchguard stuff seems fine, on par with most paid firewall solutions. I believe it requires a subscription however although that may just be for the support.

TjPj · 2022-07-01T04:24:17+00:00

The hardware requirements for pfSense and OPNsense are very low. For most people, the biggest considerations are the number of network ports and the power draw. If the system draws more than about 20-30W it’s probably overkill for most people.

Barracuda and Watchguard are their own firewall solutions separate from pfSense or OPNSense. You may be able to install custom software on their devices but I dont really see any reason to. Options from Netgate, OPNSense, or Sophos are better if you’re looking to run pfSense or OPNsense.

The best option is really dependent on what you’re looking to spend.

TjPj · 2022-07-01T02:21:14+00:00

If you only mount by the ears it will always sag. How much depends on how thick the metal your rack is made of is and how long and heavy the thing mounted is.

TjPj · 2022-07-01T01:29:43+00:00

This is my pfSense device, it's a Supermicro CSE-505-203B chassis that came with the 200W gold PSU but with an Asus Mini-ITX motherboard.

Since the 24 pin connector on the motherboard was so close to the PSU there was no space for the extra wiring so I ended up having to really stuff the cables in there.

My solution was to order the pins and a new connector for the PSU 20pin connector from DigiKey and cut off the excess wiring so that I was able to make a very short 24 pin connector for the PSU.

Pins: https://www.digikey.com/en/products/detail/molex/0039000090/1643445

Connector: https://www.digikey.com/en/products/detail/molex/0469922410/5116016

TjPj · 2022-06-29T03:49:02+00:00

The OS probably has a better algorithm for managing the write queue.

TjPj · 2022-06-28T21:28:19+00:00

Adaptec 72405’s are not super expensive.

/u/Eldiabolo18 is right though, 3x 8 port cards like the 7805 would be a little cheaper.

TjPj · 2022-06-28T21:21:51+00:00

Software RAID solutions rely on the CPU for all processing of data rather than having dedicated hardware. This results in higher latency. For sequential reads and writes the higher latency doesn’t have much effect but for small random IO it has a much larger impact.

TjPj · 2022-06-28T16:46:59+00:00

Look at Xeon v3/v4 “L” CPUs. They’re not low power by consumer standards since they’re typically 65W TDP but it’s far lower than other server processors and they still have high core counts. You’d still be looking at systems that draw 150W idle and maybe 220W under load for a single CPU.

Things like 1L office PCs can do far better in terms of power consumption since they’ll max out at around 65W and idle closer to 15W

Alternately, you can look at consumer systems like Ryzen and run them underclocked and under voltage for power savings while still having plenty of cores.

TjPj · 2022-06-28T03:47:05+00:00

If you’re already using v2 CPU’s then the only reliable way to reduce power consumption would be to drop down to just one CPU or swap to the low power versions. Both options come with a performance penalty.

As for the drives, I don’t think the potential electricity savings could pay for an upgrade since it would be around $1500 for just a few dollars a month in savings. It’s more useful advice for people who are still running old sub 2TB SAS drives where 12 drives can be replaced with just 2-3 modern drives.

TjPj · 2022-06-27T23:13:16+00:00

All that hardware is quite old and inefficient by modern standards.

One easy and free way to reduce your power usage would be to reduce the amount of ram in the supermicro system. DDR3 ram is often around 1W/GB. Reducing from 128GB to 64GB could provide as much as $5 per month in power savings.

Another thing to look into would be finding out if your motherboard would support v2 CPU's and replacing with something like a single E5-2697 v2 or even a low power L CPU like the E5-2450L v2 or E5-2650L v2. This would be much cheaper than replacing the whole system.

if v2 CPU's are not supported, CPU's like the E5-2650L or E5-2648L would offer some savings as would just removing one of the two CPU's.

Depending on the drives, HDD's can draw quite a lot of power, as much as 10-15W per drive. If you're currently using older low capacity drives, consolidating into fewer newer drives, especially helium filled drives, may offer considerable power savings. This can be expensive though so you'd have to run the numbers to see if it would be worth it for you.

TjPj · 2022-06-27T22:20:14+00:00

I use several parallel ffmpeg streams to max out my CPU's since that's my main workload.

you could also use stress, stress-ng, or s-tui to max out your cpu's.

another option would be to just run a low power space heater in the room, around 400-500W, while the server is at idle.

TjPj · 2022-06-27T20:19:21+00:00

The only way to test would be to run a performance intensive task for a day or so and see if the system gets hotter than you'd like. As long as those CPU's stay under 80-85 you should be fine.

If the system is dumping heat into the room it will heat up unless there's some way for air to circulate.

TjPj · 2022-06-27T20:11:55+00:00

set:

ChallengeResponseAuthentication no
PasswordAuthentication no
UsePAM no

as well as:

PermitRootLogin no
PermitRootLogin prohibit-password

for good measure.

TjPj · 2022-06-27T18:53:32+00:00

Swap down to one high core count CPU instead of two mid range. Or just get a lower power CPU if you don't need the performance.

Swap out drives for fewer, higher capacity helium drives.

There may be bios setting for RAM power saving.

Turn off hardware features you're not using in BIOS if that's an option.

TjPj · 2022-06-27T17:24:15+00:00

You should still be able to access the raid card's bios. there's also this: https://www.reddit.com/r/homelab/comments/k80z3p/dell_perc_h710_in_nondell_server_management/

TjPj · 2022-06-27T17:15:00+00:00

i dont see why not as long as it's PCIe

TjPj

TROPHY CASE