Virtual GPUs have three main attributes: hash rate, durability and efficiency. Base GPUs start with no durability & efficiency levels and users can level up durability and efficiency by spending MNB. Each upgrade consists of 2 rolls. The first roll determines the multiplier of the upgrade, which is essentially the ‘level’ of upgrade applied. The second roll determines the duration of the upgrade, which is how long the upgrade is applied for. The cost of an upgrade is calculated by taking 2.5% of the $ value paid for the GPU and dividing that figure by the current price of MNB, for the purpose of the example below we use $0.025.