Tesla GPU计算革命:NVIDIA与AMAX在线研讨会

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“Nvidia-AMAX Tesla GPU Computing Webinar[1].pdf” 是一份关于NVIDIA和AMAX联合举办的Webinar材料,主题聚焦于NVIDIA的Tesla GPU计算技术,展示了GPU计算在高性能计算领域的革命性影响。 正文: NVIDIA Tesla GPU计算是21世纪初高性能计算领域的一个重要里程碑。它打破了传统计算模式,引入了GPU(图形处理器)与CPU(中央处理器)协同工作的概念,即所谓的异构计算。异构计算利用GPU的并行处理能力来加速计算密集型任务,而CPU则负责系统管理和其他非并行任务,两者互补,大大提升了整体计算性能。 Tesla GPU是NVIDIA专为科学计算和高性能计算设计的系列GPU产品。例如,FASTRA项目中,通过8个Tesla GPU在桌面级系统中实现了强大的计算能力,成本仅为6000美元,而相比之下,同等性能的CalcUA超级计算机由256个节点(512个核心)组成,造价高达500万美元,这显示了GPU计算在性价比上的显著优势。 在各个应用领域,Tesla GPU展现出了惊人的加速效果。例如,在医学成像中,犹他大学报告称性能提升达到146倍;分子动力学研究中,伊利诺伊大学厄巴纳-香槟分校的实验结果显示性能提升36倍;视频转码方面,Elemental Technologies利用Tesla GPU实现了50倍的加速;而在金融模拟中,牛津大学的项目速度提高了47倍。这些案例证明,Tesla GPU不仅提供了超越常规2倍或3倍的加速,而是带来了20倍至150倍的惊人提升。 NVIDIA Tesla 10系列GPU具有大规模并行、多核架构,每个处理器核心包含了浮点/整数单元,以及用于高速数据传输的102GB/s接口到内存。此外,它还配备了特殊功能单元(SFU),TP阵列共享内存,以支持高精度计算,如双精度浮点运算,这是科学计算中必不可少的功能。这样的硬件设计使得Tesla GPU能够高效执行各种复杂的科学计算任务,如线性代数、量子化学、基因测序等,同时在3D超声波成像和金融模拟等领域也表现出色。 总结来说,NVIDIA Tesla GPU计算技术以其卓越的并行处理能力和高效能计算,改变了高性能计算的游戏规则,使得原本需要昂贵超级计算机才能完成的任务,现在可以在更经济、更小巧的设备上实现。这一技术的广泛应用和显著效果,无疑推动了科学研究和工程计算的进步,并为未来的计算架构提供了新的可能。

将下面这段源码转换为伪代码:def bfgs(fun, grad, x0, iterations, tol): """ Minimization of scalar function of one or more variables using the BFGS algorithm. Parameters ---------- fun : function Objective function. grad : function Gradient function of objective function. x0 : numpy.array, size=9 Initial value of the parameters to be estimated. iterations : int Maximum iterations of optimization algorithms. tol : float Tolerance of optimization algorithms. Returns ------- xk : numpy.array, size=9 Parameters wstimated by optimization algorithms. fval : float Objective function value at xk. grad_val : float Gradient value of objective function at xk. grad_log : numpy.array The record of gradient of objective function of each iteration. """ fval = None grad_val = None x_log = [] y_log = [] grad_log = [] x0 = asarray(x0).flatten() # iterations = len(x0) * 200 old_fval = fun(x0) gfk = grad(x0) k = 0 N = len(x0) I = np.eye(N, dtype=int) Hk = I old_old_fval = old_fval + np.linalg.norm(gfk) / 2 xk = x0 x_log = np.append(x_log, xk.T) y_log = np.append(y_log, fun(xk)) grad_log = np.append(grad_log, np.linalg.norm(xk - x_log[-1:])) gnorm = np.amax(np.abs(gfk)) while (gnorm > tol) and (k < iterations): pk = -np.dot(Hk, gfk) try: alpha, fc, gc, old_fval, old_old_fval, gfkp1 = _line_search_wolfe12(fun, grad, xk, pk, gfk, old_fval, old_old_fval, amin=1e-100, amax=1e100) except _LineSearchError: break x1 = xk + alpha * pk sk = x1 - xk xk = x1 if gfkp1 is None: gfkp1 = grad(x1) yk = gfkp1 - gfk gfk = gfkp1 k += 1 gnorm = np.amax(np.abs(gfk)) grad_log = np.append(grad_log, np.linalg.norm(xk - x_log[-1:])) x_log = np.append(x_log, xk.T) y_log = np.append(y_log, fun(xk)) if (gnorm <= tol): break if not np.isfinite(old_fval): break try: rhok = 1.0 / (np.dot(yk, sk)) except ZeroDivisionError: rhok = 1000.0 if isinf(rhok): rhok = 1000.0 A1 = I - sk[:, np.newaxis] * yk[np.newaxis, :] * rhok A2 = I - yk[:, np.newaxis] * sk[np.newaxis, :] * rhok Hk = np.dot(A1, np.dot(Hk, A2)) + (rhok * sk[:, np.newaxis] * sk[np.newaxis, :]) fval = old_fval grad_val = grad_log[-1] return xk, fval, grad_val, x_log, y_log, grad_log

2023-06-06 上传

将这段代码转换为伪代码:def levenberg_marquardt(fun, grad, jacobian, x0, iterations, tol): """ Minimization of scalar function of one or more variables using the Levenberg-Marquardt algorithm. Parameters ---------- fun : function Objective function. grad : function Gradient function of objective function. jacobian :function function of objective function. x0 : numpy.array, size=9 Initial value of the parameters to be estimated. iterations : int Maximum iterations of optimization algorithms. tol : float Tolerance of optimization algorithms. Returns ------- xk : numpy.array, size=9 Parameters wstimated by optimization algorithms. fval : float Objective function value at xk. grad_val : float Gradient value of objective function at xk. grad_log : numpy.array The record of gradient of objective function of each iteration. """ fval = None # y的最小值 grad_val = None # 梯度的最后一次下降的值 x_log = [] # x的迭代值的数组,n*9,9个参数 y_log = [] # y的迭代值的数组,一维 grad_log = [] # 梯度下降的迭代值的数组 x0 = asarray(x0).flatten() if x0.ndim == 0: x0.shape = (1,) # iterations = len(x0) * 200 k = 1 xk = x0 updateJ = 1 lamda = 0.01 old_fval = fun(x0) gfk = grad(x0) gnorm = np.amax(np.abs(gfk)) J = [None] H = [None] while (gnorm > tol) and (k < iterations): if updateJ == 1: x_log = np.append(x_log, xk.T) yk = fun(xk) y_log = np.append(y_log, yk) J = jacobian(x0) H = np.dot(J.T, J) H_lm = H + (lamda * np.eye(9)) gfk = grad(xk) pk = - np.linalg.inv(H_lm).dot(gfk) pk = pk.A.reshape(1, -1)[0] # 二维变一维 xk1 = xk + pk fval = fun(xk1) if fval < old_fval: lamda = lamda / 10 xk = xk1 old_fval = fval updateJ = 1 else: updateJ = 0 lamda = lamda * 10 gnorm = np.amax(np.abs(gfk)) k = k + 1 grad_log = np.append(grad_log, np.linalg.norm(xk - x_log[-1:])) fval = old_fval grad_val = grad_log[-1] return xk, fval, grad_val, x_log, y_log, grad_log

2023-06-06 上传

解释:def steepest_descent(fun, grad, x0, iterations, tol): """ Minimization of scalar function of one or more variables using the steepest descent algorithm. Parameters ---------- fun : function Objective function. grad : function Gradient function of objective function. x0 : numpy.array, size=9 Initial value of the parameters to be estimated. iterations : int Maximum iterations of optimization algorithms. tol : float Tolerance of optimization algorithms. Returns ------- xk : numpy.array, size=9 Parameters wstimated by optimization algorithms. fval : float Objective function value at xk. grad_val : float Gradient value of objective function at xk. grad_log : numpy.array The record of gradient of objective function of each iteration. """ fval = None grad_val = None x_log = [] y_log = [] grad_log = [] x0 = asarray(x0).flatten() # iterations = len(x0) * 200 old_fval = fun(x0) gfk = grad(x0) k = 0 old_old_fval = old_fval + np.linalg.norm(gfk) / 2 xk = x0 x_log = np.append(x_log, xk.T) y_log = np.append(y_log, fun(xk)) grad_log = np.append(grad_log, np.linalg.norm(xk - x_log[-1:])) gnorm = np.amax(np.abs(gfk)) while (gnorm > tol) and (k < iterations): pk = -gfk try: alpha, fc, gc, old_fval, old_old_fval, gfkp1 = _line_search_wolfe12(fun, grad, xk, pk, gfk, old_fval, old_old_fval, amin=1e-100, amax=1e100) except _LineSearchError: break xk = xk + alpha * pk k += 1 grad_log = np.append(grad_log, np.linalg.norm(xk - x_log[-1:])) x_log = np.append(x_log, xk.T) y_log = np.append(y_log, fun(xk)) if (gnorm <= tol): break fval = old_fval grad_val = grad_log[-1] return xk, fval, grad_val, x_log, y_log, grad_log

2023-06-06 上传