What is the point of upconverting power?

  • No tl;dr. I spent 20 mins writing this so you can bloody well read it :-)


    Hopefully you know that EU travels in packets of a certain size. So to move 1024EU from a batbox to a machine using copper cable, it's broken up into 32 separate packets of 32EU. Using gold cable it's 8 packets of 128EU or just two packets of 512EU using glass cable. A power source can only produce one packet per tick (1/20th of a second) so sources with higher voltages can move EU more quickly because they move more EU per tick. OK, that's the basics out of the way.


    All cables lose a certain amount of EU per packet, per block travelled.


    Insulated copper loses 1 EU per 5 blocks. So if you have a batbox or transformer every 5th block (only 4 bits of cable between the batboxes), you lose only 4 x 20% of an EU which is rounded down to zero EU. You never lose anything. But if you ran, say, 30 blocks of insulated copper you'd lose 6EU from each of those 32EU packets. So if you sent 20,480 EU (split up into 640 x 32EU packets), you'd only receive 16640 EU total at the other end. Also it'd take 640 ticks (32 seconds) to move it.


    HV Cable (aka Iron cable) has the highest loss per block. When properly insulated (HVx4) it can handle Extreme Voltage (EV) of 2048EU per packet. It loses 1EU per packet per 1.25 blocks. So the same 20,480 EU will be moved in only 10 packets. Each packet loses 24 EU over the 30 blocks. This is a much higher loss, per-packet, than copper cable BUT because the packets are so big there are not many of them so the total loss is less. Only 240EU (30 blocks / 1.25 x 10 packets) is lost over the 30 blocks. So you're left with 20,240 EU at the destination.


    Gold cable (MV) fits in between copper (LV) and iron (HV) cable.


    That's the basics. Higher voltages are useful for reducing the loss of EU over longer distances. This is exactly how it works in the real world. The power lines way overhead on the big towers are 11,000V compared to the 110-240V in your wall socket.


    ---


    Glass fibre cable throws a bit of a curve ball. It breaks the Copper-Gold-Iron progression because for its relatively high carrying capacity, it has Very low loss over distance. It loses only 1 EU per packet for every 40 blocks and can handle 512EU packets. So let's do a comparison in the name of SCIENCE \o/


    Let's say we have 10,000,000 EU (a full MFSU) to move over a distance of 300 blocks (from your reactor in town to your Fortress of Solitude out in the hills).


    Glass Fibre
    10,000,000 EU becomes 19,532 packets of 512 EU
    7.5 EU lost per packet over 300 blocks. Rounding up to 8 EU.
    156,256 EU total loss.
    10M EU sent, 9,843,744 arrive in 977 seconds (16.3 mins).


    HVx4 Cable
    10,000,000 EU becomes 4,883 packets of 2048 EU
    240 EU lost per packet over 300 blocks.
    1,171,920 EU total loss.
    10M EU sent, 8,828,080 arrive in 245 seconds (4 mins).


    So what do we learn from all of the above?


    In Copper, Gold and Iron, the higher tier cables can move power more efficiently. For most cases, the resource costs of the transformers is negligible. However Glass Fibre is so efficient that it's probably the best for the majority of cases. The only time that you'd want to use Extreme Voltage would be if you needed to get a Very Large amount of EU over a long distance in a real hurry. I can't think of many situations where you'd need to do that. Teleporters or terraformers perhaps?


    I use glass fibre for almost everything I do. As yet I haven't needed to run cables more than 40 blocks.


    Anyway, I hope that helps.


    If you would like the official description, it's here on the Wiki
    http://wiki.industrial-craft.net/index.php?title=Cable


    edit: Tweaked the explanations and formatting for greater clarity.

    GENERATION 26: The first time you see this, copy it into your sig on any forum and add 1 to the generation. Social experiment or chain letter? This is left as an exercise for the reader.


    Efficiency 3, 50% duty cycle. SMP friendly. Alternate two of them slowly with an rp2 sequencer for a steady 120 EU/t.
    http://www.talonfiremage.pwp.b…=1j10101001501521s1r11r10

  • The major point to argue, on the side of EV in this case is the resource cost of transference.


    To transfer the 10M EU mentioned previously over the 300 blocks would take 75 sets of fibre cables. That's 75 diamond and 150 redstone, which is a fair whack for a not altogether significant distance.


    On the other hand, the EV route would cost you 75 Ref. Iron, and 300 rubber, which equate to 33 Iron ore and 100 sticky resin (or just over a stack and a half), which makes the cost of the transport less significant, at the expense of the aforementioned 1M EU loss extra.


    Please bear in mind that this equation is not taking into account the cost of the HV transformer on each end (2 diamonds being the primary issues on that front).


    Now, I don't know about you, but the cost of 1M EU as opposed to 75 diamonds is a no brainer, in my eyes, even when you consider that it equates to a 10% loss.


    EDIT: It's 900 rubber for completely insulated HV. Also, these links might help in demonstrating and calculation:
    Resource calculator
    Cable Loss Calculator

  • The only thing I would note is that there is no capacity limit on the cables, just a per-packet size limit. You can send a million EU/tick down a tin cable as long as no packet is larger than 5E.


    The caveat is that all of the storage devices have a fixed output limit of 1 packet at max size per tick. So a MFSU spits out a 512E packet every tick if there is someone on the line that needs all of that power. The MFE only spits out 128E packets, and Batboxes deal in paltry 32E packets.


    Transformers also have a maximum conversion rate, but if you're talking about EV then you don't have to worry about it until you're generating far too much power anyway.

  • Good additions, thanks guys.


    Indeed the number of diamonds required to travel that 300 blocks is not small so that's a good reason to use EV.


    The ability to feed a single cable with multiple power sources was also mentioned to me via private message :-) Indeed I use that technique with 16 MFSU to feed my overclocked machines. Using 4 x MFSU will send the equivalent of EV down a 512EU/tick cable.

    GENERATION 26: The first time you see this, copy it into your sig on any forum and add 1 to the generation. Social experiment or chain letter? This is left as an exercise for the reader.


    Efficiency 3, 50% duty cycle. SMP friendly. Alternate two of them slowly with an rp2 sequencer for a steady 120 EU/t.
    http://www.talonfiremage.pwp.b…=1j10101001501521s1r11r10

  • With RP2 silver that's only like 50 diamonds? On SMP with a mass fab and some solars that is no biggy.
    My scenario is running a uninsulated HV cable around my base feeding it with EV and watching with joy as he creepers try to get to me (with my setup it works out at about 0.25EU/t per block or about 50EU/t for a large 50x50 base, could be halved if required).

  • I'm just curious about the new update; do the transformer upgrades allow infinite power to go into machines, or do they cap at the high voltage packet size? I just don't want to have a big crater in my shiny new world from overpowering the macerator :) .

  • There's no limit on packet count and all packets will be processed within one tick.


    You can go for an easy setup like this and feed your LV power grid from a set of transformers (mv+lv), it would be way cheaper than getting 2 separate transformer upgrades for each machine.
    :Macerator: :Intergrated Plating: :Macerator: :Intergrated Plating: :Macerator: :Intergrated Plating: :Macerator:
    :Cable: :Cable: :Cable: :LV-Transformer: :Cable: :Cable: :Cable:
    :Macerator: :Intergrated Plating: :Macerator: :Intergrated Plating: :Macerator: :Intergrated Plating: :Macerator:



    As for conversion... Gold cables (and MV overall) are completely useless, HV + HV cable is 2x more efficient than MV + gold.
    HV is fine for small distances, but when you think about really long-range transfers, it's terrifying. If you want to transfer said 10M EU over 1000 blocks, you will lose ~39% over direct transfer. These numbers are not right.

  • AFAIK the transformer upgrades are capped at HV. Sending EV into a machine with 3 transformer upgrades will still blow it up.

    Disappointed with the bugs and nerfedness of AtomicStryker Corp's Advanced Machines, and the unupdatedness of Snyke's Enterprises?
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    Battery snot included.

  • I've never actually done this yet, so correct me if I'm wrong; but for the aforementioned 300 block example, would anyone here be willing to use copper cable and batbox repeaters as mentioned, and transform the power all the way down to LV, and simply AFK or do something else in-game while the power transferred, even if it took an hour or so? It just seems as though that would still be a (relatively) cheap way of doing it, resource wise, and there is no current loss at all then, either.

  • If you would want to transfer a full MFSU worth of energy via a line of batboxes and/or transformers it would take almost four and half hours, so if you would have any EU production at all it would take ridiculously long. Even with MV you'd be better of just by going mining and making a new power plant or transferring it with a lapotron.

  • If you would want to transfer a full MFSU worth of energy via a line of batboxes and/or transformers it would take almost four and half hours, so if you would have any EU production at all it would take ridiculously long. Even with MV you'd be better of just by going mining and making a new power plant or transferring it with a lapotron.


    OK. This makes sense. :D


  • Round down.
    Thats how IC2 does it i'm pretty sure.

  • You can break the cables and reuse them though.


  • Let's say we have 10,000,000 EU (a full MFSU) to move over a distance of 300 blocks (from your reactor in town to your Fortress of Solitude out in the hills).


    Shouldn't it be from your reactor in your fortress of solitude to your town house? Most mayors I have played with on SMP aren't to keen on the idea of me plonking down a reactor in my back yard.

  • You can also hybrid the cables. Like use 5 EV cables then 1 glass fiber cable. then 5 more EV then 1 glass fiber.

    Quote

    That's a rather cool idea, but a lone tree is suspicious, better plant some more. So really... forget about solar-flowers, solar-trees are the next generation :P

  • You can also hybrid the cables. Like use 5 EV cables then 1 glass fiber cable. then 5 more EV then 1 glass fiber.


    That really only works to a point, because it's still expensive to make the necessary glass fibre cable - and sending HV through the HV cables loses around four times the EU compared to upstepping to EV and sending it all along HV cable (Glass fibre cannot send EV). If you need to make more than, say, eight Glass fibre cables (total length 53 with your example), then it's better to step up the voltage.

  • Now that we're discussing Transformers, why would you NOT convert HV to LV to power your machines directly? Is there some sort of advantage a Mass Fabricator has with HV rather than LV?

  • If you're feeding the Mass Fab using direct HV or via transformers, it receives a full 512 EU/t. If you're using a Batbox, it'll only be receiving 32 EU/t (likewise, an MFE will limit current to 128 EU/t). This can be useful knowledge if you ever want to limit the current going to the mass fab.


    Same for other machines capable of accepting MV or HV (natively or through upgrades), obviously changing 512 EU/t to 128 EU/t in the case of MV.