I was curious to find out how fast does G80 perform compared to some other boards GHI is offering. I have used @ Duke Nukem code, which was slightly modified, and I ran it on NETMF 4.3.7.8. Here are the results:
G80: 00:03:28.0820210
G120: 00:13:00.3519469
G400: 00:01:31.4454191
Hydra+: 00:05:49.8682380
Cerb40 II: 00:03:30.9686550
G400 is still a king and G120 does not look good 
G120 and G400 are the only two SoCs that offer all the goodies from GHI, however, the performance gap is huge.
Code (this website distorts my code, here is original - http://pastebin.com/Dzm9ReER):
public class Program
{
public static void Main()
{
Debug.Print("Program Started");
string x = Process(200); // calculate 200 digits of PI
Debug.Print("PI=" + x);
}
/*
* Original code: http://omegacoder.com/?p=91
* Adapted code: https://www.ghielectronics.com/community/codeshare/entry/597
*/
public static string Process(int digits)
{
var result = new StringBuilder();
result.Append("3.");
DateTime StartTime = DateTime.Now;
if (digits > 0)
{
for (int i = 0; i < digits; i += 9)
{
String ds = CalculatePiDigits(i + 1);
int digitCount = Math.Min(digits - i, 9);
if (ds.Length < 9)
//ds = string.Format("{0:D9}", int.Parse(ds));
ds = int.Parse(ds).ToString("0:D9");
result.Append(ds.Substring(0, digitCount));
}
}
TimeSpan duration = DateTime.Now.Subtract(StartTime);
Debug.Print("Time elapsed: " + duration.ToString());
return result.ToString();
}
private static int mul_mod(int a, int b, int m)
{
return (int)((a * (long)b) % m);
}
// return the inverse of x mod y
private static int inv_mod(int x, int y)
{
int q, u, v, a, c, t;
u = x;
v = y;
c = 1;
a = 0;
do
{
q = v / u;
t = c;
c = a - q * c;
a = t;
t = u;
u = v - q * u;
v = t;
} while (u != 0);
a = a % y;
if (a < 0)
{
a = y + a;
}
return a;
}
// return (a^b) mod m
private static int pow_mod(int a, int b, int m)
{
int r, aa;
r = 1;
aa = a;
while (true)
{
if ((b & 1) != 0)
{
r = mul_mod(r, aa, m);
}
b = b >> 1;
if (b == 0)
{
break;
}
aa = mul_mod(aa, aa, m);
}
return r;
}
// return true if n is prime
private static bool is_prime(int n)
{
if ((n % 2) == 0)
{
return false;
}
var r = (int)Math.Sqrt(n);
for (int i = 3; i <= r; i += 2)
{
if ((n % i) == 0)
{
return false;
}
}
return true;
}
// return the prime number immediately after n
private static int next_prime(int n)
{
do
{
n++;
} while (!is_prime(n));
return n;
}
private static string CalculatePiDigits(int n)
{
int av, vmax, num, den, s, t;
var N = (int)((n + 20) * Math.Log(10) / Math.Log(2));
double sum = 0;
for (int a = 3; a <= (2 * N); a = next_prime(a))
{
vmax = (int)(Math.Log(2 * N) / Math.Log(a));
av = 1;
for (int i = 0; i < vmax; i++)
{
av = av * a;
}
s = 0;
num = 1;
den = 1;
int v = 0;
int kq = 1;
int kq2 = 1;
for (int k = 1; k <= N; k++)
{
t = k;
if (kq >= a)
{
do
{
t = t / a;
v--;
} while ((t % a) == 0);
kq = 0;
}
kq++;
num = mul_mod(num, t, av);
t = 2 * k - 1;
if (kq2 >= a)
{
if (kq2 == a)
{
do
{
t = t / a;
v++;
} while ((t % a) == 0);
}
kq2 -= a;
}
den = mul_mod(den, t, av);
kq2 += 2;
if (v > 0)
{
t = inv_mod(den, av);
t = mul_mod(t, num, av);
t = mul_mod(t, k, av);
for (int i = v; i < vmax; i++)
{
t = mul_mod(t, a, av);
}
s += t;
if (s >= av)
{
s -= av;
}
}
}
t = pow_mod(10, n - 1, av);
s = mul_mod(s, t, av);
sum = (sum + s / (double)av) % 1.0;
}
int Resultx = (int)(sum * 1e9);
string StringResult = Resultx.ToString(); //String.Format("{0:D9}", Result));
if (StringResult.Length < 9)
{
for (int i = StringResult.Length; i < 9; i++)
{
StringResult = "0" + StringResult;
}
}
return StringResult;
}
}
