go version is 1.5 beta 1, the same was on "stock" 1.3.3 from Debian repos
OS: Debian 8.1 x64

I'm stress testing (with loader.io) this type of code in Go to create an array of 100 items along with some other basic variables and parse them all in the template:

package main

import (
    "html/template"
    "net/http"
)

var templates map[string]*template.Template

// Load templates on program initialisation
func init() {
    if templates == nil {
        templates = make(map[string]*template.Template)
    }

    templates["index.html"] = template.Must(template.ParseFiles("index.html"))
}

func handler(w http.ResponseWriter, r *http.Request) {
    type Post struct {
        Id int
        Title, Content string
    }

    var Posts [100]Post

    // Fill posts
    for i := 0; i < 100; i++ {
        Posts[i] = Post{i, "Sample Title", "Lorem Ipsum Dolor Sit Amet"}
    }

    type Page struct {
        Title, Subtitle string
        Posts [100]Post
    }

    var p Page

    p.Title = "Index Page of My Super Blog"
    p.Subtitle = "A blog about everything"
    p.Posts = Posts

    tmpl := templates["index.html"]

    tmpl.ExecuteTemplate(w, "index.html", p)
}

func main() {
    http.HandleFunc("/", handler)
    http.ListenAndServe(":8888", nil)
}

My test with Loader is using 5k concurrent connections/s through 1 minute. The problem is, just after a few seconds after starting the test, I get a high average latency (almost 10s) and as a result 5k successful responses and the test stops because it reaches the Error Rate of 50% (timeouts).

On the same machine, PHP gives 50k+.

I understand that it's not Go performance issue, but probably something related to html/template. Go can easily manage hard enough calculations a lot faster than anything like PHP of course, but when it comes to parsing the data to the template, why is it so awful?

Any workarounds, or probably I'm just doing it wrong (I'm new to Go)?

P.S. Actually even with 1 item it's exactly the same... 5-6k and stopping after huge amount of timeouts. But that's probably because the array with posts is staying of the same length.